Stephen Crabb has rejected claims that he is prejudiced against gay people as he launched a bid to be the next Tory leader and prime minister.
In an interview with BuzzFeed News on Wednesday, the work and pensions secretary said he regretted the "sadness" and "hurt" he had caused with his vote against same-sex marriage in 2013.
He also distanced himself from a Christian charity that once co-funded a conference focusing on "gay cure therapies" for "those struggling with unwanted same-sex attraction".
Crabb was an intern with Christian Action Research and Education (CARE) in the 1990s and was one of 20 MPs who took paid-for interns from them in 2012.
Asked about his links with the group, the MP for Preseli Pembrokeshire said: "I don’t think CARE has ever supported gay cure. But more importantly than that, gay cure has never been something I have believed in, it’s never been part of my beliefs.
"It forms no part of my Christian outlook. What I absolutely am committed to is fostering a culture of tolerance and respect and equality in our society and people regardless of their sexuality, regardless of what kind of relationship they’re in, whether they choose to get civil-partnered up, whether they’re gay married or not."
Pressed on whether he stood by his vote against gay marriage, Crabb said: "I’m not in the business of going back over my voting history on any issue and saying this was the right or the wrong thing.
"But that issue is settled, there was a clear vote there. I’m very, very happy with the outcome of that and when I see friends getting married to their same-sex partners, that’s a great thing. A society where people are showing total commitment to each other and choosing that path, I respect that."
Crabb is keen to present himself as the "One Nation" candidate to unite Britain after last week's divisive referendum on the European Union. But for many people, his desire to cast himself as a moderniser is difficult to square with his stance on gay marriage.
He insisted he was "totally committed" to gay rights despite his voting record. "One of the things that struck me after the vote on gay marriage was... I had probably six or seven emails from constituents who were gay and who wrote to me in that context just expressing sadness," he said.
"I remember the email of one constituent who said: ‘I’ve always known you to be a decent and compassionate person, I couldn't understand the vote and I was saddened by it.'
"And that really affected me. I don’t want any vote I make or anything I say or do to make anyone feel hurt or feel that I value them any less. So hopefully what I was able to do in that instance was demonstrate to that constituent that regardless of sexuality, his rights need to be totally respected.
"As secretary of state for work and pensions, I meet with the LGBT team in the department, they know I am totally committed to fostering a culture of equality and tolerance. There doesn’t need to be any question marks over that."
Crabb pointed to a "generational division" in society that had been laid bare by the referendum.
"I think young people will be looking for a new prime minister who understands their concerns and their sense of economic uncertainty," he said.
"Are they ever going to own their own home? What kind of job are they going to get? What kind of salaries are they going to get in the future? How will leaving the EU affect that? I think I am well placed to be able to answer and speak to those concerns."
In a press conference earlier, Crabb conceded he was the "underdog" in a leadership race that is also likely to include ex–London mayor Boris Johnson and home secretary Theresa May.
But he warned that the contest should not be a "two-horse race" between the "Boris/Stop Boris" candidates. He flagged up his working-class upbringing in Wales, saying he had a "fabulous education at a really good comprehensive school across the road from the council house where I lived".
He also took a couple of swipes at Johnson and his privileged upbringing. "On the rainy rugby fields of west Wales, I learned that it is not a question of waiting for the ball to pop out of the back of the scrum," Crabb said.
Asked whether it was a problem that he, unlike Johnson, was not a household name, Crabb replied artfully: “There are different ways you can become a household name. I’m doing it the right way, hopefully.”