A Belfast immigration tribunal was told on Tuesday that because a Derry woman did not renounce her British citizenship she therefore remained British, even though she identifies as Irish.

The tribunal was also told that the 1998 Belfast Agreement which allowed people in Northern Ireland to identify as Irish, British or both did not override the 1981 British Nationality Act.

Under the 1981 act, according to a lawyer for the British Home Office, a person born in Northern Ireland to at least one parent who had British citizenship must be identified as British.

The British Home Office at an Upper Tribunal in Belfast is appealing a First-Tier Tribunal decision which ruled in favour of Emma DeSouza, who is from Magherafelt in Co Derry.

Ms DeSouza applied for a residence card for her US-born husband Jake in December 2015. She made the application under her Irish passport. The couple married in Belfast in July 2015.

The Home Office however rejected the application deeming that Ms DeSouza was British, notwithstanding her argument that she never held a British passport.

The Home Office requested Ms DeSouza either reapply as a British citizen or renounce her British citizenship to apply as an Irish citizen.

Ms DeSouza contested that decision, citing how the Belfast Agreement allowed her to identify as Irish, British or both.

She won her appeal, but the Home Office and its minister Priti Patel are challenging that decision at the Upper Tribunal.

Tony McGleenan, QC, for the Home Office contended that the First-Tier judge made a “fundamental and egregious error of law” in ruling that the Belfast Agreement of 1998 took precedence over the British Nationality Act of 1981.

He argued that under the nationality act Ms DeSouza held British citizenship from birth. He said it was not disputed that her father was a British citizen at the time of her birth and that she therefore acquired British citizenship at birth.

The nationality act, the lawyer said, allowed for renunciation of this citizenship but Ms DeSouza did not go down that route. “As a consequence she retains her citizenship as a British citizen as she acquired it at birth,” he said.

Mr McGleenan also made a point of stating that not all elements of the Belfast Agreement were contained in the Northern Ireland Act 1998 that flowed from the Good Friday deal, and that there were no provisions in this Act that dealt with citizenship or identity.

He added that if choice was allowed to determine citizenship then it would “nullify” the British Nationality Act. It would mean that a person in Northern Ireland “would be stateless” until he or she elected to choose one citizenship or another.

“It would mean that people in Northern Ireland would not have a defined citizenship until they made an elective choice,” said Mr McGleenan.

Ronan Lavery, QC, for Ms DeSouza, cited how a judge in the House of Lords, described the Belfast Agreement as an “attempt to end decades of bloodshed and centuries of antagonism”.

“One should not underestimate the importance of identity to people in Northern Ireland,” said Mr Lavery.

He asked how British government policy could be to “foist citizenship on people who don’t want it”.

“What part of government policy is that? It is not part of government policy.”

He told the two tribunal judges who were appearing by video link from London that some people might find it difficult to understand but many people in Northern Ireland found it offensive to have a particular identity “foisted on them”.

He queried why should the British Nationality Act “be read in such a way as to cause offence and subvert the intention of the Good Friday agreement”.

Mr Lavery asked why anyone should have to renounce citizenship when that “presupposes they were British to begin with”.

He said that if Germany had won the second World War and imposed German citizenship on all British people then that would be viewed as “offensive and something the people of Britain would rail against”.

He said it would be “unthinkable” to tell someone who was gay that they were heterosexual or to tell black people they were Asian or Asian people they were black.

Mr Lavery said the Home Office’s position was contrary to the “spirit and purpose” of the Belfast Agreement.

The judges indicated that it would take them some weeks to come up with their judgment.

About 20 people turned up at the court to support Ms DeSouza and her husband including Sinn Féin MEP Martina Anderson and MP Michelle Gildernew and SDLP Assembly members Dolores Kelly and Pat Catney.

‘Huge concerns’

Outside the court after the hearing Ms DeSouza expressed suspicion that the Home Office was following a policy which would undermine the rights of people in Northern Ireland with Irish passports to enjoy many European Union rights when the UK quits the EU. She said she was “quite shocked at the degree” to which the Home Office was pursuing the case.

“There are huge concerns over how we are going to access our EU rights and entitlements post-Brexit because we are not going to be considered EU citizens, if they are going to treat everyone in Northern Ireland as British,” she said.

Ms DeSouza said the British government and Home Office was “wilfully choosing to ignore the delicate identity balance that exists here in Northern Ireland”.

“That right under the Good Friday agreement to identify and be accepted as Irish or British or both is a fundamental principle of equality and of parity of esteem,” she said.