Conservatives who oppose same-sex marriage are holding “an understandable theological and cultural position”, Windsor MP Adam Afriyie has claimed.

Writing in The Daily Telegraph, Mr Afriyie said: “Disagreeing with same-sex marriage is an understandable theological and cultural position and is not the same as homophobia.”

In a coded reference to David Cameron’s 2006 remarks of UKIP supporters resembling “loons” and “fruitcakes”, the MP wrote: “In my view, something is wrong if life-long Conservatives feel alienated, particularly when the party’s first reaction seems to be to stifle open debate or attack those with a different view.

“I cringe when I hear words like ‘fruitcake’ and ‘loon’ thrown around in an accusatory fashion and hear allegations that some of our members are not ‘true Conservatives.’ Of course, we don’t all agree on everything, but through disagreement and debate, we arrive at better answers together.”

Mr Afriyie was among 136 Tory MPs to oppose the same-sex marriage act at second reading last year. He declared: “I voted against the bill because it is not truly equal.

“I would like to see a single form of state recognition for all couples, but the bill unnecessarily creates two forms of legally recognised union.”

A self-made millionaire who grew up in Peckham, south London, Mr Afriyie was elected in 2005 for the safe Tory seat of Windsor.

In February 2013, he attempted to quash rumours of plotting a Tory leadership challenge by saying: “I will never stand against David Cameron. I am 100% supportive of David Cameron.”