In a first House of Commons vote, lawmakers voted 400 to 175 in support of the bill sponsored by Prime Minister David Cameron. Though there was opposition from Conservatives, the measure was broadly supported by both the Labour and Liberal Democrats parties.
However, the bill will have to go through more debate and an additional vote in the House of Lords on Tuesday. If the bill becomes law, same-sex couples will be able to get married in both civil and religious ceremonies.
"I am a strong believer in marriage. It helps people commit to each other and I think it is right that gay people should be able to get married too," Cameron — who did not attend the vote — said. "This is, yes, about equality. But it is also about making our society stronger," he added.