In an interview with the New Statesman, Ken Livingstone has said the Conservative party was “riddled” with homosexuality.

The Labour London mayoral candidate told the publication he condemned “hypocrisy, like some Tory MP denouncing homosexuality while they are indulging in it”.

He added: “Well, the Labour [MPs] have all come out . . . As soon as Blair got in, if you came out as lesbian or gay you immediately got a job. It was wonderful . . . you just knew the Tory party was riddled with it like everywhere else is.”

Gay Tory MP Alan Duncan said: “Many of us have managed to take this issue out of politics. It’s inexcusable for him to try to reintroduce it.”

But a spokesman for Mr Livingstone, who was London’s mayor from 2000 to 2008, told the Evening Standard: “Ken is clearly saying the advance of lesbian and gay people into politics is unequivocally a good thing. He has fought for equality for gay and lesbian people throughout his life, and the fact they are represented in all major political parties is a sign of the progress that has been made.”

In 2006, at the launch of an anti-homophobic bullying campaign spearheaded by the gay rights charity Stonewall, Livinstone told PinkNews.co.uk: “In my school of two thousand boys, roughly a third, maybe a half of them, whilst never thinking of themselves as gay, engaged in sexual acts with other boys.

“We had no idea that what we were doing was anything other than ‘naughty’ and something that our teachers frowned upon.”

He added: “It was mainly driven by the fact that we weren’t having sex. I grew up in a world where the average man didn’t lose his virginity until he was 19 and the average woman until they were 21. Many not until the night of their marriage, only after a whole day of eating and drinking, when you’re hardly going to get the best results!

“My generation has been wholly envious of the generations that followed in relation to sex.”

Mr Livingstone was criticised last year for having earned money working for an Iranian television station which led to Tory calls for him to be banned from Pride. Press TV, for which Livingstone presented a series of programmes, had its licence revoked by Ofcom last month after it was revealed to be editorially controlled by Tehran.

In 2004, Mr Livingstone invited Islamic cleric Sheikh Yusuf al-Qaradawi to City Hall. Dr Qawardi, who is banned from entering the US, has argued in the past that gays should be put to death and has also supported female genital mutilation and suicide bombings in Israel. Some of his statements have been filmed, while others were published as quotes on his personal website.

But in 2001, Mr Livingstone introduced the first gay relationships register, four years ahead of the introduction of civil partnerships. In 2010, he published an LGBT election manifesto for his campaign this year, saying he would appoint an LGBT advisory board and hold an annual Pride reception, reintroducing measures then removed by Boris Johnson.

He told the current issue of the New Statesman: “It is very hard to find anything in Boris’s career that he’s serious about. He just loves life too much to really succeed as a politician.”