The New EU-U.K. Border: Immigration Checks, Racial Profiling, and Path to Irish Reunification

I. Introduction

On January 31, 2020 at 12:00 a.m., after forty-seven years within the European Union (“EU”), the United Kingdom (“U.K.”) became the first and only country to leave the EU.[1] Created in 1921, the Republic of Ireland-Northern Ireland border (the “Northern Irish border” or the “border”) has a lengthy, complex history rooted in British colonization of the island.[2] The border divided up the island of Ireland into the majority Catholic Republic of Ireland (“Ireland”) and the majority Protestant Northern Ireland; the latter became part of the United Kingdom.[3] At the border’s creation, the Irish and U.K. governments also implemented the Common Travel Area (“CTA”) which allowed British and Irish citizens to travel freely between the two nations. [4] In the post-Brexit regime, which makes the Northern Irish border the only land border between the United Kingdom and the EU, the CTA remains in effect.[5] Despite the promise to not have immigration controls between Ireland and Northern Ireland, the reality is that informal immigration controls will exist and they likely will result in racial profiling.[6] Potential solutions to the immigration brought on by Brexit include a devolution of immigration legal authority to Northern Ireland, and maybe even the reunification of the island to simplify the island’s immigration enforcement. [7]

II. Origins of the Northern Irish Border

On May 3, 1921, the Government of Ireland Act of 1920 (“the Act”) established the border between Northern Ireland and the Irish Free State (renamed the Republic of Ireland in 1949).[8] Prior to this border creation, the British and its predecessors occupied the island of Ireland since the late twelfth century when the Normans invaded.[9] This marked the beginning of more than 700 years of British occupation and colonialism in Ireland.[10] During the seventeenth century, the British implemented a policy called “Plantation” for its Protestant citizenry to settle in the Irish Province of Ulster.[11] Due to this policy, the “religious composition of Ulster changed from predominately Catholic to predominantly Protestant.”[12] The rest of Ireland remained majority Catholic.[13]

In 1920, the Ulster Unionists, who were mostly Protestant and sought to remain within the United Kingdom, achieved their goal with the Government of Ireland Act of 1920.[14] Through the Act, the British government partitioned Ireland, “offering nationalists a parliament in Dublin and giving Ulster unionists their own parliament in Belfast.”[15] Yet, the Nationalists in the south, who were majority Catholic, “mostly ignored” the Act’s mechanics.[16] Instead, the Nationalists pursued independence from the United Kingdom.[17] The resultant War of Independence lasted about two years and concluded with the signing of the Anglo-Irish Treaty (“the Treaty”) on December 6, 1921.[18] The Treaty created the Irish Free State, a “self-governing dominion within the British Empire,” which included twenty-six of the island’s thirty-two counties.[19] Even though the Act partitioned Northern Ireland from Southern Ireland, the Treaty “applied to the entire island.”[20] The Treaty contained an opt-out provision for Northern Ireland, which stated if “an address is presented to His Majesty by both Houses of the Parliament of Northern Ireland…the powers of the…Irish Free State shall no longer extent to Northern Ireland.”[21] A year after the signing of the Treaty, the parliament of Northern Ireland exercised the opt-out provision and joined the United Kingdom.[22]

The establishment of the Irish Free State in 1922 is linked to the implementation of a Common Travel Area.[23] The CTA is “a special travel zone covering the Republic of Ireland and the United Kingdom.” where “British and Irish citizens can travel within the CTA without being legally required to carry a passport.”[24] The main principle behind the CTA is that the Irish and U.K. governments treat each other’s citizens in “a similar manner” so that they can “freely move between the two jurisdictions” without “special permission.”[25] The Irish and U.K. governments have maintained the CTA since Irish independence, only pausing its operation once during World War II.[26]

The Act and Treaty were not the end of problems between the Northern Ireland and the Republic of Ireland.[27] In fact, the division of Ulster’s provinces into Northern Ireland and the Irish Free State highlighted the basis of the problems over the century’s remainder. A letter from a Catholic living in Northern Ireland in 1922 explains the situation:

The root cause of the trouble here is that the Catholics and the Nationalists feel that Ulster was unfairly divided by the 1920 Act…[A]ll of Ulster was not taken as a unit, it was cut up in such a way as to empower 820,000 Protestants to rule over 420,000 Catholics. The result being that Catholics will not enter the Northern Parliament.[28]

Beginning in the 1960s, the religious divisions sparked decades of violence dubbed “The Troubles,” a term applied to the “murderous ethno-religious conflict.”[29] During the Troubles, from the late 1960s until 1998, the Republic of Ireland-Northern Ireland border became a militarized zone “studded with British Army checkpoints and was the scene of regular [Irish Republican Army] attacks.”[30] In fact, only twenty official border crossings existed between Northern Ireland and the Republic of Ireland, which heavily restricted the movement of people.[31] The violence between the Catholics who sought a unified Ireland and the Protestants who aimed to keep Northern Ireland within the United Kingdom led to over 3,500 deaths.[32] In 1993, Human Rights Watch published a report outlining human rights abuses in Northern Ireland.[33] The abuses included “killings by paramilitary groups and security forces, street harassment by security forces, ill-treatment in detention, problems in obtaining a fair trial, the abandonment of normal policing in some troubled areas and ill-treatment by paramilitary organizations.”[34]

Credited with ending the Troubles, the 1998 Good Friday Agreement (“the Agreement”) ended direct British rule, set up a Northern Ireland government with power shared between unionist and nationalist parties, and withdrew border checkpoints.[35] The result of the Agreement meant an “all-but-invisible” border between Northern Ireland and the Republic of Ireland through which people and goods passed through freely.[36] The Agreement also included a clause that if the majority in Northern Ireland wished to leave the United Kingdom and form part of a “united Ireland,” it may by the Secretary of State laying before U.K. Parliament.[37] Thus, if Northern Ireland wishes, it could leave the United Kingdom and reunify with Ireland.[38] After the Agreement, the British military took down checkpoints on the border and removed its last watchtowers in Northern Ireland in 2006.[39]

III. Republic of Ireland-Northern Ireland Border in a Post-Brexit World

(a) Joining and Leaving the EU

Amidst the Troubles, in 1973, the United Kingdom and the Republic of Ireland joined the predecessor to the EU called the European Communities.[40] In 1993, the Maastricht Treaty formally created the EU, and a trade agreement launched the European Single Market, which allows for the free movement of “people, goods, services and money.”[41] The mechanism that allows for people “to travel freely without border checks” in the EU is the Schengen area.[42] It currently includes all EU member states except Ireland and Cyprus (the United Kingdom was not a part of the Schengen area when it was in the EU).[43] Ireland and the United Kingdom did not join the Schengen area because both nations prefer to maintain the CTA.[44]

Securing the United Kingdom’s borders was a key issue that British voters considered when deciding whether to leave the EU.[45] In fact, the U.K. Independence Party’s (“UKIP”) leave campaign focused on restricting immigration, with slogans like, “We want our country back: Vote to Leave.”[46] Ultimately, the leave campaign won, and the United Kingdom left the EU on January 31, 2020.[47] In the post-Brexit regime, the Northern Irish border is the only land border between the United Kingdom and the EU.[48] As the only land border, and given the border’s history of violence during the Troubles, the Northern Irish border was uniquely situated in Brexit negotiations.[49] Since it is the external border between the United Kingdom and the EU, it naturally would follow that a “hard” border should exist there given that the two entities have different laws on immigration and customs.[50] A “general fear” existed that the return of a hard border “would lead to anger, and, potentially violence.”[51] However, Ireland, Northern Ireland, and the rest of the United Kingdom, and the EU all wanted to avoid a hard border.[52]

(b) The 2019 Memorandum on the CTA & the Protocol

After nearly three years of Brexit negotiations, in May 2019, the U.K. and Irish governments signed a memorandum of understanding, stating that they “reaffirm[ed]” the CTA “and the associated reciprocal rights and privileges enjoyed by Irish and British citizens in each other’s state.”[53] The memorandum continues that the CTA “existed long before” the EU and therefore are “not dependent on” EU membership.[54] The Irish and U.K. governments “consider it desirable…to reaffirm” that the CTA arrangements continue after the United Kingdom’s withdrawal from the EU.[55]

A few months after the memorandum on the CTA, U.K. Prime Minister Boris Johnson and President of the European Commission Jean-Claude Juncker announced the Protocol on Ireland/Northern Ireland (“the Protocol”).[56] The Protocol avoids a hard border by effectively keeping Northern Ireland in the EU’s Single Market for goods.[57] The Irish Sea Border thus became the customs border with the United Kingdom—although the U.K. government rejects the term “Irish Sea Border.”[58]

As for immigration, Article 3 of the Protocol states that the CTA can continue after Brexit: “The United Kingdom and Ireland may continue to make arrangements between themselves relating to the movement of persons between their territories (the ‘[CTA]’).”[59] The Protocol also reaffirms the Good Friday Agreement, specifically, that “no diminution of rights, safeguard, or equality of opportunity” will result from the United Kingdom’s withdrawal from the EU.[60] The United Kingdom promised to continue “the related work of the institutions and bodies set up” by the Good Friday Agreement, including the Northern Ireland Human Rights Commission to “uphold[] human rights and equality standards.”[61]

(c) Impacts on Immigration within the CTA

While the CTA provides that Irish and British citizens can travel between Ireland and the United Kingdom without border stops, the United Kingdom’s electronic travel authorizations (“ETAs”) “will make it illegal for some people to enter the United Kingdom without a visa where they previously could.”[62] An ETA is a “digital permission” to travel to the United Kingdom.[63] These ETAs will require non-visa nationals to “get advanced permission to enter the United Kingdom.”[64] The ETA scheme opened February 1, 2024 for nationals of Bahrain, Kuwait, Oman, the United Arab Emirates, Saudi Arabia, and Jordan.[65] It “is due to be in place for all relevant nationalities by the end of 2024, although it will not be enforced until 2025.”[66]

The legal basis for the ETA scheme is § 75 of the Nationality and Borders Act 2022.[67] During the deliberations for this Act, the U.K. House of Commons rejected a proposed exemption for people traveling from Ireland to Northern Ireland.[68] A member of U.K. Parliament stated that the proposed exemption “could result in an unacceptable gap in U.K. border security that would allow persons of interest or risk who would be otherwise refused an [ETA] to enter the United Kingdom legally.”[69] Therefore, as the ETA scheme implements, non-Irish and non-British nationals will need to gain an ETA prior to crossing the Northern Irish border.[70]

Since, as the U.K. government stresses, “no immigration controls” will exist “whatsoever on the [Northern Irish border],” a question remains for how the U.K. government will enforce the ETAs. [71] The U.K. government asserts that if an individual encounters an immigration official, they will need to “provide physical evidence that demonstrates that they are legally resident in Ireland.”[72] Further, it will be a criminal violation of the Immigration Act of 1971 to “knowingly enter” the United Kingdom without an ETA where one is required.[73]

Concerns exist that actions will be taken which might have “serious human rights implications for minority ethnic communities” in Northern Ireland.[74] A primary worry is that these “ad-hoc” immigration checks will be executed on the basis of racial profiling. [75] Since the immigration checks will be impromptu, an increased likelihood exists that immigration officers will make their stops based on racial profiling, where individuals are targeted because of their skin color or other ethnic characteristics.[76] As a result, an increased use of “administrative detentions” of  those who “cannot ‘satisfy’ immigration officers” is likely to occur.[77] In sum, although the U.K. government promised to have no immigration controls on the Northern Irish border; in reality, ad hoc checks—that could disproportionately impact ethnic minorities—will occur as the ETA scheme rolls out.

IV. Solutions to Post-Brexit Immigration Issues

Solving post-Brexit immigration issues require a human rights focused approach and may even potentially result in a reunified Ireland. Fidelma O’Hagan, the solicitor for a human rights organization in Northern Ireland called the Committee on the Administration of Justice, suggests that “a more human rights focused approach” is necessary to solve the immigration issues affecting Ireland and Northern Ireland.[78] An example of a human rights focused approach is a devolved immigration legal system which would allow for “regionally-led immigration systems,” which in turn, will increase “democratic and public accountability” for immigration policy.[79] O’Hagan calls on Northern Ireland to “support the call” for transferring control over immigration policy from the broader United Kingdom.[80]

Another, but more drastic, solution is the reunification of the island. Brexit has focused many Irish Nationalists, who seek the reunification of the island, on the Good Friday Agreement’s reunification provision.[81] The Secretary of Northern Ireland is the one who holds the power under the Good Friday Agreement to order the “holding of a poll.”[82] And, the current Secretary of State is Chris Heaton-Harris, a British politician and member of the British Conservative Party, who is unlikely to call such a poll.[83] Despite this, Northern Ireland may after all draw closer to reunification as Michelle O’Neill, a member of the Sinn Fein party (supportive of Irish reunification), became the First Minister of Northern Ireland on February 3, 2024.[84] As the United Kingdom’s ETA scheme spreads, leaders and human rights watchers must settle on a solution to minimize racial profiling and prevent a hard border that could reignite violence.

V. Conclusion

After years of negotiations following the Brexit vote in 2016, the U.K. and Irish governments decided to keep the CTA, which, first established in 1922, allows Irish and U.K. citizens to travel freely between Ireland and the United Kingdom.[85] While all sides (Ireland, the United Kingdom, and the EU) desired to avoid a hard border post-Brexit,[86] the reality is that immigration checks are unavoidable, especially with the implementation of the United Kingdom’s ETA scheme. [87] The new ETA scheme likely will result in racially-profiled immigration checks.[88] Solutions to this issue include a devolution of immigration legal authority to Northern Ireland, and possibly even the reunification of the island to simplify the island’s immigration enforcement. [89]

Created in 1921, the Northern Irish border has existed for over 100 years. [90] Its history is one of colonization, compromise, and violence—colonization for the years of British rule on the island of Ireland; compromise for the end of British rule on the island, but for the price of losing territory on the north of the island (Northern Ireland); and violence for the decades of death and terror during the Troubles. Today another descriptor can be added to the list: uncertainty—uncertainty for its future and its position in the post-Brexit world.

[1] Timeline: The EU-UK Withdrawal Agreement, European Council (last updated May 30, 2023),

[2] Thomas Bartlett, Ireland: A History, at 36 (2010).

[3] Ian N. Gregory, Niall A. Cunningham, C.D. Lloyd, Ian G. Shuttleworth & Paul S. Ell, Continuous Division, 1920s-1960s, Troubled Geographies: A Spatial History of Religion and Society in Ireland (Dec. 27, 2013),

[4] CJ McKinney, Michael Potter, & Terry McGuinness, The Common Travel Area and the Special Status of Irish Citizens in UK Law, House of Commons Library (Aug. 16, 2023),,or%20Ireland%20without%20immigration%20restrictions.

[5] Eimear Flanagan, NI 100: Tracing the History of the 100-Year-Old Irish Border, BBC (May 2, 2021),; Memorandum of Understanding between the Government of Ireland and the Government of the United Kingdom of Great Britain and Northern Ireland Concerning the Common Travel Area and Associated Reciprocal Rights and Privileges, Ir.-U.K., May 8, 2019, [hereinafter Memorandum of Understanding].

[6] Fidelma O’Hagan, Brexit and Immigration Control in Northern Ireland, BrexitLawNI (last visited Feb. 16, 2024),

[7] Id.; Sinn Fein’s Michelle O’Neill Appointed Northern Ireland’s First Minister, Al Jazeera (Feb. 3, 2024),’s%20Michelle%20O’Neill%20has%20been%20formally%20appointed%20Northern,United%20Kingdom%20territory’s%20devolved%20government.

[8] David Torrance, The Northern Ireland Border, House of Commons Library (Mar. 30, 2023),

[9] Bartlett, supra note 2, at 36.

[10] Id. From the Norman invasion in 1169 until Irish independence in 1921, Ireland was under English occupation—a total of 752 years.

[11] Torrance, supra note 8, at 6; see Appendix I for map of the island (most of Ulster is within Northern Ireland today).

[12] Id.; see Appendix I: Map of Ireland. The island of Ireland is made up of four provinces: Connacht, Leinster, Munster, and Ulster. Ulster contains nine of the thirty-two counties in Ireland. Northern Ireland currently is comprised of six of the nine Ulster counties.

[13] Ian N. Gregory, Niall A. Cunningham, C.D. Lloyd, Ian G. Shuttleworth & Paul S. Ell, supra note 3.

[14] Torrance, supra note 8, at 10-11; Flanagan, supra note 5.

[15] Id.; Government of Ireland Act of 1920, “[T]here shall be established for Southern Ireland a Parliament to be called the Parliament of Southern Ireland…and there shall be established for Northern Ireland a Parliament to be called the Parliament of Northern Ireland…For the purposes of this Act, Northern Ireland shall consist of the parliamentary counties of Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone, and the parliamentary boroughs of Belfast and Londonderry, and Southern Ireland shall consist of so much of Ireland as is not comprised within the said parliamentary counties and boroughs.”

[16] Sarah Tudor, Government of Ireland Act 1920: What System Did It Create?, UK Parliament: House of Lords Library (Dec. 9, 2020),

[17] Id.

[18] Bartlett, supra note 2, at 406. After “impassioned and frequently embittered debate” in the Irish parliament, the treaty was finally approved by [a] narrow margin” on January 7, 1922.

[19] Tudor, supra note 16.

[20] Id.

[21] Anglo-Irish Treaty (Dec. 6, 1921),

[22] David Torrance, The Anglo-Irish Treaty, 1921, House of Commons Library (Dec. 5, 2022),

[23] CJ McKinney, Michael Potter, & Terry McGuinness, supra note 4.

[24] Id. at 6.

[25] Common Travel Area Information Note from Ireland to the Article 50 Working Group, Republic of Ireland’s department of Foreign Affairs, (last visited Feb. 16, 2024).

[26] Id.

[27] Torrance, supra note 22, at 50. The Ireland Act 1949 “removed the last remaining functions of the British Crown in relation to Ireland.” Ireland Act 1949,

[28] Charles McLorinan, Letter to the British Lord Chancellor, The National Archives (June 1, 1922),

[29] Bartlett, supra note 2, at 469.

[30] Flanagan, supra note 5.

[31] Nuala McCann & Christina McSorley, The Hardest Border, BBC (May 31, 2017),

[32] Ian N. Gregory, Niall A. Cunningham, C.D. Lloyd, Ian G. Shuttleworth & Paul S. Ell, supra note 3.

[33] Northern Ireland: Human Rights Abuses by All Sides, Helsinki Watch (May 1993),

[34] Id.

[35] Jill Lawless, As It Turns 25, N Ireland’s Good Friday Agreement Explained, Associated Press (Apr. 17, 2023),

[36] Id.

[37] The Good Friday Agreement (1998),

[38] Id.

[39] Flanagan, supra note 5; Bartlett, supra note 2, at 568. The Good Friday Agreement was amended in October 2006 with the St. Andrews Agreement.

[40] European Commission, Ireland in the EU, Representation in Ireland,,Ireland%20in%20the%20EU,referendum%20held%20on%2010%20May (last visited Feb. 4, 2024). The European Communities were comprised of the European Coal and Steel Community, the European Economic Community, and the European Atomic Energy Community. The U.K. and the Republic of Ireland’s membership in the European Communities began on Jan. 1, 1973.

[41] History of the European Union 1990-99, European Union, (last visited Feb. 27, 2024).

[42] Directorate-General for Communication, Travelling in the EU: Your Rights & EU Rules, European Union,’s%20kept%20growing,than%20400%20million%20EU%20nationals (last visited on Feb. 17, 2024).

[43] FAQ: What Countries Are Schengen States?, Germany’s Federal Foreign Office,,the%20Schengen%20Agreement%20and%20are (last visited Feb. 17, 2024); European Commission, Europe Without Borders: The Schengen Area, Migration and Home Affairs (June 3, 2015),

[44] Schengen: Controversial EU Free Movement Deal Explained, BBC (Apr. 24, 2016),

[45] O’Hagan, supra note 6.

[46] Nicholas Watt, EU Referendum: Vote Leave Focuses on Immigration, BBC (May 25, 2016),

[47] Flanagan, supra note 5.

[48] Id.

[49] Danica Kirka, Northern Ireland’s History Makes Post-Brexit Deal Complex, AP (Feb. 28, 2023),

[50] Simon Carswell, Brexit Explained: Why Does the Border Matter and What is the Backstop?, The Irish Times (Apr. 29, 2019), A “hard” border is “a frontier monitored and protected by customs officials and border inspectors, and potentially police or military personnel if there are security issues around the border.”

[51] Id.; Mark Daly, Pat Dolan & Professor Mark Brennan, Northern Ireland Returning to Violence as a Result of a Hard Border due to Brexit or a Rushed Border Poll: Risks for Youth (Feb. 18, 2019), “In as little as six weeks it is possible that a hard border could materialize due to a no deal Brexit, triggering a return to violence in Northern Ireland.”

[52] Samuel Petrequin, EU’s Barnier Says Irish Border Issue Could Lead to Failure, AP (Oct. 19, 2018), The EU’s chief negotiator Michel Barnier said, “avoiding such a ‘hard border’ is a ‘condition for peace and stability for this island following many tragedies’ and that the issue has the potential for the talks to end in failure.” Niamh Lyon, Brexit Will Not Mean Hard Borders, Leaders Vow, The Sunday Times (Jan. 31, 2017), “Securing agreement on ‘seamless and frictionless’ trade and travel across the border will be the shared key objective” of Brexit negotiations for the leaders of the Republic Ireland and the U.K.

[53] Memorandum of Understanding, supra note 5.

[54] Id. at 2.

[55] Id.

[56] Lisa O’Carroll, How is Boris Johnson’s Brexit Deal Different from Theresa May’s?, The Guardian (Oct. 17, 2019),

[57] Protocol on Ireland/Northern Ireland, EU-U.K., Jan. 24, 2020, The “substantive provisions” of the Protocol started to apply on Jan. 1, 2021.

[58] Torrance, supra note 8, at 42-43. On the first day that the Protocol was effective, Brandon Lewis, the Secretary of State for Northern Ireland, tweeted that “There is no ‘Irish Sea Border.’”

[59] Protocol on Ireland/Northern Ireland, supra note 57, at Article 3.

[60] Id., at Article 2.

[61] Id.

[62] Id.

[63] Electronic Travel Authorisation (ETA) Scheme Factsheet, The United Kingdom’s Home Office in the Media (Feb. 1, 2024),

[64] CJ McKinney, Michael Potter, & Terry McGuinness, supra note 4, at 19.

[65] Electronic Travel Authorisation (ETA) Scheme Factsheet, supra note 63.

[66] CJ McKinney, Michael Potter, & Terry McGuinness, supra note 4, at 20.

[67] Id.

[68] Id.

[69] Nationality and Borders Bill, House of Commons (debated Mar. 22, 2022),; see CJ McKinney, Michael Potter, & Terry McGuinness, supra note 4, at 20.

[70] Electronic Travel Authorisation (ETA) Scheme Factsheet, supra note 63.

[71] Id.

[72] Lord Murray of Blidworth, Corrected Oral Evidence: Statement of Changes to the Immigration Rules and Immigration (Electronic Travel Authorisations) (Consequential Amendment) Regulations 2023, House of Lords (May 11, 2023),; see CJ McKinney, Michael Potter, & Terry McGuinness, supra note 4, at 21.

[73] Id.; see Immigration Act 1971, § 24(D1),

[74] O’Hagan, supra note 6.

[75] Id.

[76] Id.

[77] Id.

[78] Id.

[79] Id.

[80] Id.

[81] Flanagan, supra note 5.

[82] The Good Friday Agreement, supra note 37.

[83] Chris Heaton-Harris, About Chris, Chris Heaton-Harris: Conservative MP for Daventry, (last visited Feb. 4, 2024).

[84] Sinn Fein’s Michelle O’Neill, supra note 7.

[85] Memorandum of Understanding, supra note 5.

[86] Petrequin, supra note 52.

[87] Lord Murray of Blidworth, supra note 72.

[88] O’Hagan, supra note 6.

[89] Id.; Sinn Fein’s Michelle O’Neill, supra note 7.

[90] Torrance, supra note 8.