The House of Commons, including MP for Peterborough Lisa Forbes, has backed plans to extend same-sex marriage and abortion to Northern Ireland if devolution is not restored.
MPs voted by a margin of 383 to 73 to introduce marriage equality in an amendment to the Northern Ireland Assembly.
They also backed improving abortion access by 332 to 99. Both votes were “conscience votes” and not whipped.
The Government has said it will honour the result, despite some ministers expressing concerns, including prospective Prime Ministers Boris Johnson and Jeremy Hunt.
Stormont has been suspended since 2017 due to major parties being unable to agree on key issues, including same-sex marriage.
If the Assembly does not agree a power sharing deal within three months, Westminster’s ruling will automatically come into force.
A future devolved government could approve or repeal the measure.
Before the vote the Northern Ireland minister, John Penrose, said the Gvernment would honour the result: “Should this pass it will go into law. It will become part of primary legislation. And so ministers will be bound by it and the Government will proceed.”
Same-sex marriage was legalised in Scotland and in England and Wales in 2014.
Labour MP Stella Creasy tabled an amendment to ensure women in Northern Ireland can access a safe, legal and local abortion.
In the rest of the UK abortion was legalised in 1967 and is available for women who have not reached their 24th week of pregnancy and have the permission of two doctors. In Northern Ireland it is only legal in extreme circumstances.
The successful amendment argued that the UK government is obliged to extend the law to do this to comply with human rights obligations.
Speaking before the vote, Ms Creasy said: “We have to remember there is no right at all, not even in those instances of rape, of fatal fetal abnormality. We force women in Northern Ireland to carry a baby they know will not live under these current laws - that cannot be a human right.
“It is why this is torture, and it is why we cannot keep waiting for the Assembly to deal with this.”
MP for North West Cambridgeshire Shailesh Vara did not vote.