In what is the most visible sign of the split between Lib Dems and the Tories on the issue of equal marriage, the Deputy Prime Minister, Nick Clegg, has said that the issue cannot be left to individual conscience.

Reacting to the recent announcement by Commons Leader, Sir George Young, that this was a ‘matter of conscience,’ and therefore will be subject to a free vote among the Tories, the Lib Dem leader said: “We are not asking any person with religious convictions to sacrifice anything,” adding, “We are simply saying those who want to show a lifelong commitment to each other should be able to do so.”

Distancing himself from the Prime Minister, he said it was up to David Cameron if he wanted to force his MPs on the matter, but said Lib Dems would ‘honour what we have said as a party.’ “He’s a leader of his party, I am leader of mine,” he said.

Speaking to BBC’s Andrew Marr, Mr Clegg said: “In the same way the civil partnerships legislation which was introduced under Labour was a whipped vote, I personally don’t think this is something which should be subject to a great free for all because we are not asking people to make a decision of conscience.”

Echoing the warning he issued to Tories against backing down on equal marriage, he added: “If this was an issue that somehow the Government was proposing something that would somehow be an imposition on religion or the churches, then of course that would be a matter of conscience. We are not.”

On the day that the free vote was announced, Theresa May, the Conservative Home Secretary recorded a video for the Out4Marriage campaign where she said: “Today I wanted to tell you about my own views. I believe in marriage. I believe marriage is a really important institution, it’s one of the most important institutions we have. Marriage binds us together, it brings stability, I think marriage makes us stronger. But I believe also in commitment and in fidelity in marriage, I think these are good things and we should enable them to flourish.

“That’s why I believe if two people care for each other, if they love each other, if they want to commit to each other and spend the rest of their lives together then they should be able to get married, and marriage should be for everyone, and that’s why I’m coming Out4Marriage.”