More than 100 Conservative MPs are threatening to rebel against their leader’s plan for fully equal gay marriage.

British Prime Minister David Cameron will give his MPs a free vote on gay marriage but they will be urged to support it’s introduction.

Calling for full civil marriage equality, Cameron famously told his party conference in October: ‘Yes, it's about equality, but it's also about something else: commitment. Conservatives believe in the ties that bind us; that society is stronger when we make vows to each other and support each other. So I don't support gay marriage despite being a Conservative. I support gay marriage because I'm a Conservative.’

But not all MPs in the traditional wing of the party agree and now some are threatening to rebel on the issue, reports The Independent.

The paper reports a party source saying that ‘feelings are running high’ and predicts the rebellion could be worse for Cameron than the 81 of his MPs who voted against his government on Europe.

With MPs from the Conservatives’ Liberal Democrat coalition partners and the main opposition party, Labour, both broadly signed up to same-sex marriage equality, the rebels may stand little chance of success in defeating the change.

But David Burrowes, one of the organisers of the campaign against equality, told The Independent he is ‘cautiously optimistic’.

He added: ‘Many colleagues are worried that it would fundamentally affect how marriage between a man and woman has historically been viewed in this country. There are strong doubts that we need to go down this path. It would open up a can of worms and a legal minefield about freedom, religion and equalities legislation.

‘Gay marriage is a debate we don't need to have at this stage. It is not an issue people are hammering us on the doorstep to do something about. It is important that there is a reasoned debate around how we view marriage rather than about homosexual rights. It may open up old wounds and put people into the trenches; no one wants that.’

Gay marriage has long been strongly supported by the Liberal Democrats but was not included in the coalition agreement which tied the two parties together to form a government.

When government plans to equalise marriage were announced, it was seen by some commentators as a Conservative gift to their coalition colleagues.

Lynne Featherstone, the Liberal Democrat Equalities minister and driving force behind the change, will go ahead with a consultation process on marriage laws in March, to be followed by legislation.

And the LGBT+ Liberal Democrats group has reaffirmed its commitment to equality in the face of the threatened Conservative revolt.

Chair Adrian Trett said: ‘As the only major party to support equal marriage, we will continue to work hard to bring it about, working with supporters from all parties and none.’

Gay Star News also contacted the lesbian, gay, bisexual and transgender groups of the Labour and Conservative parties for their comments and we will update you when we receive a reply.