Home > Tenants > Greg Ó Ceallaigh

Greg Ó Ceallaigh

  • Call: 2006
"He has an impressive grasp of a wide range of complex immigration matters."

Legal 500, 2019

"He fights extraordinarily hard on detention and asylum cases." "Exceptionally intelligent, hardworking and great to work with." "The go-to counsel for third country issues."

Legal 500 and Chambers UK Bar Guide


Greg specialises in human rights, asylum and immigration law. He is ranked in the Chambers UK Bar Guide 2019 and the Legal 500 2019 (Tier 2) for immigration.

“I am always impressed by the clarity of his written work, his general approachableness, and his grasp of a wide range of complex immigration matters. He is also very communicative and easy to work with.”
Chambers UK 2019

“He is very good, very personable, and his pleadings are very good. He’s an expert in immigration certification cases.”
 Chambers UK 2018

“He is an excellent barrister; you know you’re in safe hands due to his attention to detail.”
Legal 500 2017

“He is completely on top of Italy third-country case litigation.” “He fights extraordinarily hard on detention and asylum cases.”
Chambers UK 2017

Approachable, supportive, reliable and good-humoured.”
Legal 500 2016

“He is very tactically astute and is a no-nonsense barrister.” “He has been amazing with a lot of the third country removal cases.”
Chambers UK 2016

“Exceptionally intelligent, hardworking and great to work with.”
Legal 500 2015

Greg’s substantial public law practice primarily involves judicial reviews of immigration decisions, notably in detention, nationality, third country, age assessment and children’s long residence matters. He has much experience of urgent removal cases and is comfortable taking instructions at short notice.

Greg’s immigration tribunal work consists of asylum, human rights, deportation, detention, citizenship/nationality, work and education visas, family reunion and other entry clearance cases. Greg is an experienced Tribunal advocate both at the First Tier and the Upper Tribunal.

Greg has significant expertise in immigration detention and has represented detainees at every level from the Tribunal to the Administrative Court, as well as in civil actions for false imprisonment. He frequently appears pro bono on behalf of Bail for Immigration Detainees. Greg has built up particular expertise at challenging removal to third countries under the Dublin system notably Italy, in relation to which he was instructed in the test cases of AB (Sudan) v SSHD [2013] EWCA Civ 92, Tabrizagh and others v SSHD [2014] EWHC 1914 (Admin), R(Tesfay) v SSHD [2014] EWHC 4048 (Admin) and MS and others v SSHD [2015] EWHC 1095 (Admin).

Greg is one of the authors of Butterworths’ Immigration Law Service, where he has responsibility for the chapters on Immigration Detention, Illegal Entry, Removal and Deportation, and General (including concessions and the Immigration Rules).

Greg is a regular contributor to Free Movement, and has been featured in national and international press as an expert on immigration issues and the refugee crisis, including the Independent, Wall Street Journal, RTS and Al Jazeera.

Greg is eligible to take work on a Direct Access basis.

In addition to his public law and immigration practice, Greg has experience of advising and representing clients in discipline cases before the Health Professions Council.

Notable Cases

Fardous v SSHD [2015] EWCA Civ 931
Successfully defended SSHD appeal of the case of Fardous v SSHD [2014] EWHC 3061 (QBD) in which a Moroccan national won his action for false imprisonment. Led by Stephanie Harrison QC.

Dudaev and Ors v SSHD [2015] EWHC 1641 (Admin)
Case challenging the lawfulness of Sch 3 to the 2004 Act involving the proposed return to Sweden under Dublin procedures of Chechen exiles.

MS and others v SSHD [2015] EWHC 1095 (Admin)
Latest test case challenging lawfulness to Dublin returns to Italy. Currently pending before the Court of Appeal.

R(AMG) v SSHD [2015] EWHC 5 (Admin)
Case challenging the lawfulness of immigration detention of a severe ill man repeatedly detained under the Mental Health Act. Currently pending before the Court of Appeal.

R(Tesfay) v SSHD [2014] EWHC 4048 (Admin)
Test case dealing with the implications of the SSHD withdrawing all decisions rendered unlawful following EM(Eritrea) v SSHD [2014] UKSC 12. Currently pending before the Court of Appeal.

Tabrizagh and others v SSHD [2014] EWHC 1914 (Admin)
Test case challenging the lawfulness of removals to Italy pursuant to Dublin II.

R (Ismail) v SSHD [2013] EWHC 3921 (Admin)
Successful challenge to the unlawful detention of a Somali national pending a decision to deport and deportation proceedings.

SHL (Afghanistan) v SSHD [2013] UKUT 312 (IAC)
Case involving a trafficked minor and justiciability of the Trafficking Convention, reliance on evidence obtained from a child interviewed when encountered without an appropriate adult, and the relevance of a failure to comply with the SSHD’s obligation to trace.

AB (Sudan) v SSHD [2013] EWCA Civ 921
Test case on whether there should be stays on all Dublin II Regulation removals to Italy pending the Supreme Court’s consideration of the application for permission to appeal in EM (Eritrea) v SSHD [2012] EWCA Civ 1336 (See also AB (Sudan) v SSHD [2013] EWCA Civ 16 and R (Bushara) v SSHD [2012] EWHC 3483 (Admin)).

R (ZSS) v SSHD [2013] EWHC 1619 (Admin)
Challenge to the detention of a child on the basis of an unseen and non-Merton compliant age assessment and the refusal to accept evidence as a fresh claim.

R (Paul) v SSHD [2013] EWHC 1317 (Admin)
Challenge to the lawfulness of 30 months’ detention with an allegation of non-cooperation, permission having been granted by the Court of Appeal following refusal in the Administrative Court.

R (AK) v SSHD [2011] EWHC 3188 (Admin)
Successful challenge to the lawfulness of the detention of a disputed minor (settled following grant of permission).

R (AH) v Croydon County Council
Successful challenge to the age assessment of a disputed minor (settled following grant of permission).

R (JK) v SSHD and Hampshire County Council
Successful challenge to the age assessment of a disputed minor (settled following grant of permission).

Ncube v United Kingdom [2012] ECHR 897
Successful challenge in the European Court of Human Rights to removal in a case of substantial long residence.

R (Cheung) v Secretary of State for the Home Department [2011] EWHC 2337 (Admin)
Challenge to the SSHD’s refusal of leave to remain under the seven-year child concession DP 5/96 (settled following grant of permission to the Court of Appeal).

R (Abdullah) v Secretary of State for the Home Department (2010) QBD
Successful challenge, as a junior, to the SSHD’s detention of the claimant for three years.

R (Kumlachew) v Secretary of State for the Home Department
Judicial review of the SSHD’s refusal to grant citizenship following compulsory involvement in the Dergue regime (citizenship granted with costs following grant of permission).

PK (Zimbabwe) v Secretary of State for the Home Department
Appeal to Court of Appeal following misapplication of RN (Zimbabwe). Appeal allowed by consent following grant of permission, costs awarded.

Pro Bono and Community Work

Greg undertakes a large volume of pro bono work in immigration law, including for Bail for Immigration Detainees.

Greg was a runner-up at the Bar Pro Bono Award 2009 with a team from Tooks Chambers for work on an application to the Human Rights Appeal Panel in Kosovo on behalf of the family of Mon Balaj.

Greg previously worked on a team writing the legal arguments for an amicus curiae on behalf of Binyam Mohammed (detained at the time in Guantanamo Bay), in Hamdan v Rumsfeld in the United States Supreme Court.


Greg trained at Garden Court Chambers and Tooks Chambers before becoming a tenant at 1 Pump Court. He re-joined Garden Court Chambers in August 2013.

Before pupillage Greg worked as a researcher for Keir Starmer QC, the former Director of Public Prosecutions. He was a paralegal at Janes Solicitors while volunteering at the AIRE Centre advising on European law and human rights to members of the public. He assisted in research for Blackstone’s Guide to the Identity Cards Act 2006.

Greg has a degree in Philosophy and English from Trinity College Dublin and a Masters’ Degree in Legal and Political Theory from University College London. He completed his CPE at City University and BVC at the Inns of Court School of Law.

In 2005 Greg was awarded a Gold Medal for Oratory by the University Philosophical Society of Trinity College Dublin.

In 2006 Greg was awarded the Otto Rix Scholarship by the Honourable Society of the Inner Temple.


Greg considers himself a triathlete based on very limited evidence. He enjoys playing and watching football.