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Declan O'Callaghan

Declan O'Callaghan



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Public Law

Declan practices in all areas of public law and appears at all levels of domestic courts, particularly the High Court and the Court of Appeal. He places a strong emphasis on civil liberties and anti-discrimination. 

He has a strong knowledge of international human rights law including the securing of rights under the European Convention of Human Rights and has experience in applications direct to the European Court of Human Rights. He enjoys advising on all matters of European Union law. 

He has acted as a leading junior counsel in the Court of Appeal on several occasions. 

He has been instructed in a wide range of judicial review applications before the High Court, including matters concerning asylum, immigration, community care, education and social security.

Asylum and Immigration

Chambers and Partners confirm that Declan is “vastly experienced” (2017), ‘continues to lead the pack on cases relating to immigration’ (2016), is “an accomplished public lawyer, adept in his handling of complex international human rights, asylum and EU free movement cases” (2015) and “an immigration specialist with crossover knowledge in matters involving EU law. He is an expert on unlawful detention” (2014). He is described as “very reliable, very easy to approach and particularly good with Article 8 medical cases” and “very user-friendly and very good. He’s a good one to go to for the more unusual cases” (2015).

Legal 500 confirms Declan to be ‘extremely knowledgeable on all immigration matters, particularly EEA rights’ (2017), to possess a “wide spectrum of knowledge that he brings to individual cases.” (2016). He is identified as a“brilliant advocate” (2015), “very approachable and knowledgeable” (2014) with “great interest in clients’ businesses” in business immigration matters (2013). 

Declan has a well-established reputation in asylum and immigration matters, including business immigration, having appeared in numerous test cases and several reported cases. He has a strong knowledge of the Dublin Regulations and the application of the Citizens Directive through domestic regulations. 

He has also regularly appeared in detention matters, often on an expedited basis, and advises upon damages for detention. 

He is happy and willing to undertake emergency applications to stay removal. 

Declan represents in SIAC matters relating to deportation and nationality. 

Community Care 

Declan has regularly advised and represented in community care matters, including applications addressing social care needs which are to be met by local authorities under the National Assistance Act 1948, charges relating to residential care, the planning of care and the delivery of care services. 

Declan has a particular interest in the continuing health care responsibilities of the NHS and in representing those with significant addiction, mental health and learning disability difficulties. 

Court of Protection 

Declan is regularly instructed to advise and represent in Court of Protection matters and has a strong interest in issues of capacity that flow across the wide range of public law areas in which he works. 


Declan has regularly represented in and advised upon matters concerning admission, exclusion and special educational needs. 

He advises on matters where complex needs require consideration of the inter-relationship between education and medical needs. 

He has advised local authorities on issues of discrimination, behaviour support plans and with regard to issues arising from home tuition. 


Declan has represented in social housing matters for many years, enjoying strong professional relationships with a number of solicitors. His particular area of interest is that of homelessness, though he has represented in possession and disrepair matters for over a decade. 

He has experience of a wide range of possession claims, both for tenants and local authorities, and has regularly represented in matters brought on the grounds of nuisance and anti-social behaviour as well as rent arrears. 

He has advised on matters of succession, disrepair, housing allocation, interim accommodation, decanting and committal applications. 

Local Government 

Declan is regularly instructed in local government matters concerning social housing, education, social welfare and community care. 

He has advised on a wide-range of issues, ranging from confidentiality and negligence, to procurement and prosecutions. 

He has regularly presented seminars to local authority lawyers. 

Social Welfare 

Declan has a strong interest in representing in social welfare matters, including advising migrants and those with disability as to their social security rights. He has a particular interest in matters concerning European Union law. 

He continues to represent in the First-Tier Tribunal (Social Security and Child Support) and in the Upper Tribunal. 

In recent times, he has been instructed on several occasions in matters concerning housing benefit challenges, the impact of inheritance or damages awarded by a court upon benefit claims, child support departure appeals and an appeal against the main formula maintenance assessment that required extensive cross-examination to establish that a number of witnesses were deliberately lying in order to significantly affect his client’s position.