Northern Ireland's strict abortion law subjects women and girls to "inhuman and degrading" treatment, the UK's highest court has heard.

A panel of Supreme Court justices in London were also told that the current law - which makes it an offence for a woman to abort with a foetus with a life-limiting condition or where the pregnancy arises through rape or incest - discriminates against them on the grounds of sex.

The submissions were made by Nathalie Lieven QC at the beginning of a three-day appeal brought by the Northern Ireland Human Rights Commission.

Ms Lieven argued on behalf of the commission that the prohibitions also amounted to an "unjustified" breach of their personal right to autonomy.

She also read evidence from three women relating to their experiences of being unable to have an abortion in Northern Ireland, despite the diagnosis of life-limiting conditions.

Ms Lieven described their "trauma and humiliation" and said they were forced to go through "physical and mental torture".

The proceedings before a panel of seven justices, headed by Supreme Court president Lady Hale, follow earlier legal rulings in Northern Ireland on the issue.

Unlike other parts of the UK, the 1967 Abortion Act does not extend to Northern Ireland.

Abortion is illegal except where a woman's life is at risk or there is a permanent or serious danger to her mental or physical health.

Anyone who unlawfully carries out an abortion could be jailed for life.

The commission argues that the current law's effect on women is incompatible with rights under the European Convention on Human Rights.

The High Court in Belfast made a declaration in December 2015 that the criminal law was incompatible with Article 8 of the ECHR, the right to respect for private and family life, because of the absence of exceptions to the general prohibition on abortion in cases of a foetus having a life-limiting condition and pregnancies resulting from sexual offences.

But that decision was overturned in June this year by three of Northern Ireland's most senior judges.

The appeal judges said the law in Northern Ireland should be left to the Stormont Assembly and not judges, saying that the complex moral and religious questions behind the issue should be determined by a legislature rather than a court.

The Northern Ireland Assembly voted in February last year against legalising abortion in cases of a foetus with a life-limiting condition and rape or incest.

A life-limiting condition means doctors believe an unborn child has a terminal condition and will die in the womb or shortly after birth.

The justices are being asked to rule on two issues - whether the current legislation is incompatible with Article 8 and other articles which provide protection from torture and inhuman or degrading treatment or punishment and from discrimination, including on the ground of sex; and whether the Northern Ireland Act 1998 entitles the NIHRC to bring the proceedings under the Human Rights Act 1998 to seek a declaration of incompatibility.

The Stormont Executive's senior legal adviser, Attorney General John Larkin QC, with the Justice Department, argue that the commission does not have legal power to bring the case and says it has failed to identify an unlawful act.