Despite abortion being legal in England Scotland and Wales, the 1967 Abortion Act does not extend to Northern Ireland, meaning that 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. Attempts to procure abortion pills for women in Northern Ireland have been met with threat of prosecution.

The case, which got underway this morning (October 24) is expected to last for three days.

The day's proceedings, which take place in London before a panel of seven Supreme Court justices, follow several earlier legal rulings in Northern Ireland on the controversial issue.

The Northern Ireland Human Rights Commission (NIHRC), an independent body established following the 1998 Good Friday Agreement, argued in 2014 that the current law's effect on women is incompatible with rights under the European Convention on Human Rights (ECHR).

The High Court in Belfast then made a declaration in December 2015 that the criminal law was incompatible with Article 8 of the ECHR. But that decision was overturned in June 2017 by three of Northern Ireland's most senior judges.

The appeal judges said the matter should be left to the Stormont Assembly and not judges, arguing that the moral and religious questions behind the issue should be determined by a legislature rather than a court. They also said that the issue should go before the UK's Supreme Court.

The Northern Ireland Assembly voted in February 2016 against legalising abortion in cases of fatal foetal abnormality and rape or incest.

The Supreme Court has today begun hearing a challenge by the NIHRC against the ruling of the appeal judges.

The Supreme Court hearing is due to last until Thursday.

You watch the hearing live each day here.