GAY marriage could open the door to polygamy, an MP warned last night.

Calder Valley Conservative Craig Whittaker spoke out against same-sex unions yesterday – but a party colleague in a neighbouring seat disagreed.

“When homosexuality was decriminalised in England only 45 years ago, could politicians of the day ever imagine that their successors would be looking at changing the law and re-defining marriage?

“I doubt that very much and feel that they changed the law on grounds of what we would call today ‘equality’. Legal equality, taken forward and rightfully strengthened in many avenues over those years culminating in legal civil partnerships,” said Mr Whittaker.

“If we do indeed change legislation to allow same-sex marriage now, then what will our successors be discussing and have to legislate for in the future? Polygamy? Three-way relationships? Who knows what else?”

Mr Whittaker said he would oppose the coalition Government’s proposal to legalise gay marriage by 2015.

The Home Office is currently holding a consultation on the issue.

“Marriage has a unique place in our society. It is a bedrock institution and the most stable environment for raising children. Redefining marriage would make marriage adult-centred rather than child-centred,” said Mr Whittaker.

“Civil partnerships already provide all the legal benefits of marriage so there’s no need to redefine marriage.

“It’s not discriminatory to support traditional marriage. Same-sex couples may choose to have a civil partnership but I feel that no-one has the right to redefine marriage for the rest of society.

“It is for these reasons that I feel that I am unable to support Government proposals on same-sex marriage and will be voting against the Government on this issue – if indeed it comes to a vote.”

But Mr Whittaker’s Conservative colleague Jason McCartney told the Examiner he supports gay marriage.

“I’m someone of the modern world and I want people to be happy,” said the Colne Valley MP.

“Marriage is a good thing and it should be open to people regardless of gender.”

Mr McCartney added that the proposed change would not affect religious groups.

“It wouldn’t impose any obligation on churches. It would allow people to get married in a civil marriage,” he said.

The Conservative added that his constituents didn’t appear to be interested in the issue.

“I’ve received 18 emails about this and a few letters,” he said.

“On some issues, like the NHS, I get hundreds of letters.”

Huddersfield MP Barry Sheerman agreed that voters weren’t concerned about the matter.

“I’ve had very little correspondence on gay marriage,” said the Labour man.

Mr Sheerman believes there is no need to legalise same-sex marriage.

“My friends and colleagues who are part of the gay community don’t seem to be emphasising this,” he said.

“They say that they have the rights to live a full and equal role in society.

“I think we should listen to the arguments on this and see how we go but I don’t take an ideological view.

“I’m an active Christian and I don’t have a particular stance on this issue.

“At the moment I don’t see a great pressure to go beyond civil partnerships”.