The Government must not listen to the Tory right-wing and throw plans to introduce same-sex marriage into the long grass, shadow equalities minister Yvette Cooper has said.
She also said religious leaders who backed the coalition's plans must receive political support, attacking critics who claimed to support religious freedom but were opposing the rights of others to hold gay marriages.
Speaking at the Labour party conference in Manchester, Ms Cooper said: "We can build a fairer society, we have done it before.
"We mustn't chuck this into the long grass because of an obsession of the Tory right. People who love each other want to get married. We shouldn't discriminate, we should celebrate. It is time to change the law now.
"I believe that the Government should go further. We respect freedom of religion and that means different faiths will make their own decisions. But freedom of religion also means we should also support the Quakers, the Unitarians, Liberal Judaism, and other faiths who want to celebrate same-sex marriage too and we should change the law to support them to do so."
Last week, Labour leader Ed Miliband said he not only supported the right of churches and other religious institutions to hold gay weddings, but said the plans should be extended to other faith groups as well.
He said the introduction of same-sex marriages was a sign that Britain was a "modern country". In a video recorded for the Out4Marriage campaign, he said: "We've come a long way on gay and lesbian rights in the last two decades - civil partnerships, age of consent, a range of other things - but I know there's further to go.
"We need full marriage equality, not a half-step that continues to deny gay couples the right to marry in churches, synagogues and meeting houses that are happy to accommodate them. We hope and trust that the Government will come to the same conclusion as the Labour Party."