A teenager and her mother who are fighting for women from Northern Ireland to receive free abortions on the NHS in England are to have their case aired at the UK's highest court today.
Supreme Court justices will hear their challenge against a ruling which went against them at the Court of Appeal last year.
After a day of legal argument, the Supreme Court's deputy president Lady Hale and four other judges are expected to reserve their decision and give their ruling at a later date.
During the Court of Appeal proceedings, Lord Justice Moore-Bick, Lord Justice Elias and Lord Justice McCombe heard that the case was of considerable importance as an estimated 2,000 women and girls from Northern Ireland - where abortion is illegal apart from in exceptional circumstances - come to England for terminations every year.
The young woman at the centre of the case, who is now 19, was 15 in October 2012 when she and her mother travelled from Northern Ireland to Manchester and was told she had to pay hundreds of pounds for a private termination because she was excluded from free abortion services.
She and her mother, who cannot be named for legal reasons - and are referred to in court as A and B - originally lost their action in the High Court in London in May 2014 when a judge ruled that the exclusion was lawful.
When the case was before the High Court, Mr Justice King ruled that the Health Secretary was entitled to adopt a residence-based system so that women resident in Northern Ireland are not entitled to benefit from NHS abortion services in England, even though they are UK citizens.
He declared A had no right under Article 8 (right to privacy and family life) of the European Convention on Human Rights to a state-funded abortion, and there was no breach of anti-discrimination laws under Article 14.
The appeal judges heard from Stephen Cragg QC, for the teenager and her mother, that the situation was causing desperation and stress for women and girls.
Lawful abortions were only available in rare, highly exceptional circumstances in Northern Ireland, which did not include, for example, rape, incest or foetal abnormality.
Lord Justice Elias, announcing the Court of Appeal's decision, said: ''There was nothing irrational in the approach of the Secretary of State. It is entirely logical to provide a range of NHS services throughout the UK on the basis of local residence requirements.''
Angela Jackman, a partner at law firm Simpson Millar, who has been representing the girl and her mother throughout the legal process, said: "For women in Northern Ireland who are pregnant and seek a termination, the status quo is almost unbearable.
"I believe the legal arguments of the Secretary of State are perverse and contrary to its international obligations.
"Many women face the choice between an unlawful termination using dangerous and illegal pills, with the prospect of prosecution to follow, or a costly journey to England where they must pay privately for an abortion. For many women, those costs are prohibitive.
"This is the end of a long and significant domestic journey. I am pleased that the issue is finally being given due consideration by the Supreme Court, the importance of which cannot be underestimated."