Northern Ireland remains the only country in the United Kingdom where abortion is still illegal.
But there have been growing calls for a change in the law, particularly after a referendum in the Republic of Ireland which overturned its ban on abortion in May.
In exchange for a £1bn financial package, the DUP's 10 Westminster MPs will give her a working parliamentary majority and support on certain issues.
However, it puts the prime minister in a difficult position when it comes to supporting a change in Northern Irish law.
What is the law on abortion in Northern Ireland?
It is currently illegal to have an abortion in the country, under laws dating back to the Offences against the Person Act 1861. The maximum sentence is life.
Abortion is only permitted when there is a risk to the life of the mother, or a serious risk to her physical or mental health. In such an instance, women can have the termination in an NHS or private clinic in Northern Ireland.
However, the majority of women seeking an abortion travel to England, Scotland or Wales. Last year, the government introduced a travel grant for low income women making this journey.
In 2015, the High Court in Belfast ruled that Northern Ireland’s law on abortion was not compatible with the European Convention on Human Rights - specifically as it lacks provision for cases of fatal foetal abnormality, or where the pregnancy is the result of rape or incest.
Why is this different to the rest of the UK?
The Abortion Act of 1967 legalised abortion on certain grounds in Great Britain, but this did not extend to Northern Ireland.
Health was one of the devolved powers transferred to the Northern Ireland Assembly which was created in 1998. Therefore any change to abortion laws must be made there.
However, political support has long been lacking from both sides of the political divide.
The DUP are fundamentally opposed to abortion, while Sinn Fein have been moving slowly towards supporting reform, while remaining careful not to alienate their Catholic support base. The party successfully supported lifting the abortion ban in the referendum in the Republic of Ireland.
Regardless, the Northern Ireland Assembly is currently not sitting, after power-sharing collapsed in January 2017. Until another Executive is formed, abortion reform is one of many important issues which cannot be resolved.
Can the law be changed at Westminster in the absence of the Northern Ireland Assembly?
Since the Northern Ireland Assembly has not been sitting for almost two years, there now exists a grey area over what powers Westminster has to legislate on the region’s issues.
While the UK government could impose direct rule on Northern Ireland, they have thus far refused to do so, as it would be seen to destabilise the peace process as set out in the 1998 Good Friday Agreement.
Instead, Northern Ireland has been strung along on emergency budgeting and the decision making of civil servants.
Some politicians in Westminster have called for the House of Commons to take action on abortion, and on same sex marriage, in the absence of power-sharing in Northern Ireland. This is something which is opposed by the DUP.
After the Republic of Ireland voted to lift the ban on abortion in May, Theresa May refused to give MPs in Westminster a free vote on legalising abortion in Northern Ireland, amid pressure from her partners in the DUP.
This week, Labour MPs intend to put more pressure on the government by introducing a series of Commons votes aimed at ending the abortion ban in Northern Ireland.
What is public opinion on abortion in Northern Ireland?
A YouGov poll carried out in October 2018 found that 75 per cent of people in Northern Ireland want the abortion law to change, with 65 per cent agreeing that abortion should not be a crime.
In the absence of the Northern Ireland Assembly, 66 per cent of people thought that Westminster should legislate to reform the law.
This was the first poll carried out on abortion in Northern Ireland after a referendum in the Republic of Ireland voted to lift the constitutional ban on abortion in May. It is believed that the public conversation around the referendum, and the momentum which built around the cause have contributed to a growing desire for change north of the border too.
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