The attempt by Bermuda to ban same-sex marriage will damage Britain’s international reputation if it is allowed to go ahead, a politician warned yesterday.

Chris Bryant, who will lead a debate on the controversy in the House of Commons on Monday, told The Royal Gazette that the British Government should block a Bill designed to replace same-sex marriage with civil partnerships.

The Domestic Partnership Act, which aims to reverse a Supreme Court ruling last May that opened the way for gay marriages, has yet to be signed into law by John Rankin, the Governor.

Mr Bryant said: “I think Britain will harm its reputation internationally for leading on such issues as this when we basically say ‘yes, in one of our overseas territories, which has a strong link to the United Kingdom and has the same queen, we are prepared to sanction getting rid of same-sex marriage’.”

He added: “I used to be a minister in the Church of England. I understand some people’s religious issues around all this, but 200 years ago the Church of England still thought slavery was OK.

“I think in 200 years’ time, Christians will be saying ‘why weren’t we celebrating love?’. Lots of Christians do, of course.”

Mr Bryant, a former Overseas Territories Minister at the Foreign Office, was speaking after he was given a half-hour adjournment debate on the Bermuda Bill, to be held at the end of Monday’s session at Westminster.

He will speak for 15 minutes before Boris Johnson, the Foreign Secretary, responds for the Government.

Mr Bryant, the opposition Labour MP for Rhondda in Wales, said: “I’ll say I think the Government should always sit down with politicians in each of the overseas territories and try not to get to these standoffs.

“I think the only legitimate position for a government that supports same-sex marriage is to say to those territories it must stand there as it does here in the United Kingdom.”

Mr Bryant added he “very much” valued the links between the UK and its overseas territories.

He said: “I think of British citizens in Bermuda as being just as much a British citizen as a constituent of mine in Rhondda.”

He added the close ties meant the UK was prepared to step in with help last year when Caribbean territories were hammered by hurricanes.

Mr Bryant, who entered into a civil partnership in 2010, said: “That’s the kind of link we want to retain.”

He added he believed Britain, where same-sex marriage was introduced in 2014, had a duty to intervene in Bermuda, as it should in Northern Ireland, where marriage equality is also illegal.

Same-sex marriage in the province was blocked by the Democratic Unionist Party in 2015, despite support from a majority of Northern Ireland Assembly members.

Mr Bryant said: “I would be telling the Government to do the same in Northern Ireland. When Labour was in government and we introduced civil partnerships, we said they had to happen in Northern Ireland.”

The backbencher added that a reversal of marriage equality by the island’s government would signal to gay couples who have already wed that they were “not really” married, even if those marriages would still be considered legal.

Mr Bryant said: “In the past, people thought homosexuality was something you chose. You chose to have sex with other men or other women.”

But he added no one could seriously hold that view today.

He said: “You’d be hard pressed to find a serious psychiatrist in the world who thinks it’s a mental health problem or that it’s a choice. I say God made me this way. I don’t think he would want me to live rejected by society or without the opportunity that love affords.”

Monday’s debate will not result in a parliamentary resolution, but Mr Bryant said he hoped the British Government would pledge to stand by same-sex marriage and stand by its “strong links” with Bermuda.

The Foreign Office said this month that it was “disappointed” by the Domestic Partnership Act, which passed in Parliament last month.

But a spokeswoman added that “this is a matter for the Bermuda Government acting within the terms of the Bermuda Constitution and in accordance with international law”.