An advocate of curing homosexuality has been selected as the UKIP Greater London Authority candidate for Kingston and Richmond, prompting the party’s leading gay rights activist to quit.

Alan Craig, the former Christian Peoples Alliance leader who defected to UKIP last year, was chosen as the party’s south west London GLA candidate at a hustings on Friday night over prominent LGBT activist Richard Hendron.

In an open letter circulated by Mr Hendron after the hustings he alleged he had been subjected to “homophobic abuse” and a “hate campaign” during his time as a member.

The barrister and former police officer also claimed that five of his previous applications for UKIP seats had been “lost” in the past.

He said: “Since raising my head above the parapet promoting LGBT issues in UKIP, I have seen the most vile homophobic abuse, witnessed intolerance like I have never seen before and been subject to a hate campaign.

“Senior UKIP officials have not only failed to act, support and intervene, but have also been the perpetrators.

“The straw that broke the camels back is not so much a straw but a ton of bricks.”

Mr Hendron has been an outspoken critic of his party saying last year that UKIP was perceived as “overflowing with homophobes, racist and bigots” and criticising Nigel Farage’s remarks about HIV during the election.

Mr Craig came under fire in 2015 when he compared gay rights activists to Nazis branding them the “Gaystapo” and was set to speak at a Transformation Potential conference where the idea that same-sex attraction can be cured is explored.

A spokesman for UKIP, which is the only party fielding a gay London Mayor candidate told LGBT magazine Pink News: “UKIP is proud that in Peter Whittle we have the only gay mayoral candidate and top of our Assembly list.

“That we have other candidates who have differing views merely illustrates our broad and inclusive approach”.