Labour leader Ed Miliband has recorded a video in support of gay marriage, and said same-sex weddings should be allowed in churches.
His call goes further than the policy being proposed by the Tory-Lib Dem coalition Government which only proposes to allow gay marriages in civic settings.
But supporters of traditional marriage have accused all party leaders of playing politics with marriage and being out of touch with the priorities of ordinary people.
Colin Hart of the Coalition for Marriage said: “Party leaders should stop using the institution of marriage as a political weapon to beat their opponents.
“Poll after poll shows that a majority of the public oppose these changes.
“Voters have not had the opportunity to have their say and even within the gay community, it is not a priority.
Out of touch
“The public is crying out for leadership which will revive the economy and improve our public services, but the party leaders at Westminster are obsessed with issues like gay marriage.
“They’re completely out of touch with the real needs of millions of ordinary people.
“People need action on the economy, not videos on rewriting the meaning of marriage.”
In the video Mr Miliband said: “I think, whether you are gay or straight, you should be able to signify your commitment, your love with the term marriage.”
He also commented that “we will be pushing the Government to get on with the process of legislating for equal marriage, and we’ll also be saying to them, that where faith groups want to provide that opportunity for gay couples as well as straight couples, they should be able to do so”.
Earlier this year Lord Brennan, a senior QC and Labour Peer, warned that English law could refer to fathers and mothers with terms like “Progenitor A” and “Progenitor B” if marriage is redefined.
Lord Brennan pointed to evidence from countries that have already legalised same-sex marriage, which he said led to the erosion of terms such as ‘husband’ and ‘wife’.
He argued that such a move would require amendments to laws dating back to 1285.
In August this year homosexual celebrity Christopher Biggins said he thinks “civil partnerships are fantastic” but does not see the need for same-sex marriage.