The UK parliament on Tuesday backed amendments that would compel the government to extend same-sex marriage to Northern Ireland and liberalise abortion if the country is unable to re-establish its own devolved government by October 21.
Lawmakers backed the same-sex marriage amendment 383 to 73, while the abortion amendment went through with 332 votes to 99.
Northern Ireland minister John Penrose said ahead of the vote that the government would honour the result: “It will become part of primary legislation. And so ministers will be bound by it and the government will proceed.”
Northern Ireland is the only part of the United Kingdom where same-sex marriage is not allowed, while abortion is forbidden except where a mother's life is at risk.
Earlier this year, thousands of people marched through Belfast to demand the recognition of same-sex marriage.
Previous attempts to legislate for same-sex marriage have been blocked by the Democratic Unionist Party (DUP), a key ally of British Prime Minister Theresa May, despite opinion polls in recent years showing most in the region are in favour.
Advocacy groups have called on the government to bypass the frozen local assembly and introduce legislation in the British parliament in Westminster.
Love Equality Northern Ireland, a group which had long campaigned in favour of the new legislation, took to Twitter to praise the outcome of today's vote.
"LGBT people in Northern Ireland will be waking up a little more equal tomorrow," the group said.
Patrick Corrigan of Amnesty UK hailed a "huge double-win for human rights in Northern Ireland."
Ahead of the vote, North Belfast MP Nigel Dodds voiced his opposition to the equal marriage bill, saying it is "seeking to drive a coach and horses through the principle of devolution, overriding the concerns of people in Northern Ireland".
Northern Ireland executive deadlock
Northern Ireland has been without a devolved executive for over two years since Irish nationalists Sinn Fein withdrew from the compulsory power-sharing government with the pro-British DUP.
On-off talks to restore the executive resumed in May after a hiatus of more than a year but have made no obvious progress, with the Irish government saying key issues remained as of last week.