Women’s rights and pro-choice groups marched in Northern Ireland’s capital Belfast on May 28 demanding that UK Prime Minister Theresa May extend the same abortion rights to Ulster’s residents to bring the region in line with the rest of the UK.

Since the 1967 Abortion Act, the UK has a relatively liberal abortion regime that does not apply to Northern Ireland.

Conservative Protestants and Catholics oppose a liberalisation of the existing abortion regime. According to the BBC, this forces up to three women a day travel from Northern Ireland to other parts of the UK to have an abortion, while at the same time a booming black market for abortion pills is thriving.

The most recent demonstrations targeted the offices of Northern Ireland’s main political parties, including those of the Democratic Unionist Party, which lends its support to May’s government. The second biggest party in Northern Ireland – Sinn Fein, the political wing of the IRA – has not committed to a pro-choice position.

A statement from May’s office evaded the demonstrator’s calls, arguing that abortion legislation was a matter for the local government, which in this case does not apply as Belfast does not have a unity government and is ruled directly from London.

Pressure on May is mounting in the UK’s House of Commons as a group of 160 MPs, including Conservatives, have signed a letter authored by Labour MP Stella Creasy, saying the government should pass legislation that relaxes abortion rules in Northern Ireland. T

Some Conservative MPs are calling for a referendum comparable to the recent poll that took place in Ireland, which saw a majority of Irish voters cast their ballot in favour of repealing their constitution which prohibited abortions, even in cases of incest, rape, or fetal abnormality.

Abortions in Ireland are currently only allowed if a doctor certifies that a woman’s life is at risk, a law that also applied to Northern Ireland, despite the North being a constituent member of the UK. With the new constitutional repeal,  the law will now apply only to Northern Ireland.