Theresa May should allow a free Commons vote on abortion law reform in Northern Ireland, senior Tory MP Dr Sarah Wollaston has said.
The Prime Minister faces a political headache over the issue because her fragile administration depends on the support of 10 DUP MPs, who strongly oppose any reform.
But Dr Wollaston argued that the deal with the DUP would not be affected as the supply-and-confidence arrangement does not "extend to social policy in matters such as this".
Dr Wollaston, who chairs the Commons health and social care committee, said that the forthcoming domestic violence bill offered "a real opportunity" to give Northern Irish women the same rights other British women have enjoyed since the Abortion Act was passed in 1967.
She said: "We feel that this is an opportunity for the Prime Minister to make it clear that there will be a free vote on this issue and that she welcomes a cross-party amendment so that we can actually make sure that there is fairness across the whole of the United Kingdom.
"What we're seeking from the Prime Minister is an assurance that she won't delay the domestic violence bill and that she will make sure that it is a free vote.
"The pattern has always been for things like this, that are matters of conscience, they are not whipped votes along party lines."
Downing Street insisted that abortion law was a matter for the Assembly.
However, a No.10 spokesman added: "In the past there has been a free vote but I'm not going to comment on hypotheticals."
He continued: "It is important to recognise that the people of Northern Ireland are entitled to their own process which is run by elected politicians."
Tory Brexiteer Jacob Rees-Mogg, a staunch Catholic who opposes abortion, also insisted yesterday that "this issue is one of devolution". He added: "This responsibility is devolved to Northern Ireland and if you respect our constitutional settlement then these issues ought to be decided in the right place."