Toby Young has quit his post with the higher education watchdog with an apology for his misogynistic and homophobic comments – just two days after Theresa May backed him to stay.

The controversial journalist threw in the towel amid a hail of criticism over his offensive comments about women’s breasts, gay people, the disabled and starving children in Africa.

The decision is a huge embarrassment for the Prime Minister who cleared Mr Young to remain in his job at the Office for Students board, provided he did not repeat the offensive tweets and articles.

Boris Johnson, the Foreign Secretary, and Environment Secretary Michael Gove were among other ministers who praised Mr Young, and argued he was ideal for the role.

In the Commons yesterday, universities minister Jo Johnson refused to rethink the appointment, telling MPs: “We want to encourage Mr Young to develop the best sides of his personality.”

But in an early morning statement, the free schools champion announced he was standing down from the universities regulator – after just 8 days – because his appointment had “become a distraction”.

Writing in The Spectator, Mr Young said: “The caricature drawn of me in the last seven days, particularly on social media, has been unrecognisable to anyone who knows me.

“I am a passionate supporter of inclusion and helping the most disadvantaged, as I hope my track record of setting up and supporting new schools demonstrates.

“But some of the things I said before I got involved in education, when I was a journalistic provocateur, were either ill-judged or just plain wrong – and I unreservedly apologise.”

The resignation was welcomed by Angela Rayner, Labour’s Shadow Education Secretary, but she said it “cast great doubt on the judgment” of the Prime Minister who had failed to sack him.

She tweeted: “Yesterday we had the spectacle of government universities minister defending his appointment in Parliament, he had to go. Tory cronyism could not save his job...”

A petition calling for Mr Young to be sacked had gathered more than 219,000 signatures, and some senior Conservative MPs had echoed the call.

Speaking in Monday’s debate, Robert Halfon, the education select committee chairman who has cerebral palsy, attacked the “dark” and “dangerous” articles written by Mr Young in the past.

“What I’m more concerned about is some quite dark articles where he talks about the disabled, where he talks about the working classes, and much more significantly in 2015 – and I have the article here – on what he calls progressive eugenics,” he said.

And fellow Tory Sarah Wollaston said: “I’m afraid I feel Mr Young’s comments do cross a line and are therein indicative of an underlying character, and the kind of person that would tweet comments to a woman that talk about masturbating over images of refugees.”

However, in an interview on Sunday, Mrs May chose to stand by Mr Young, saying she had been unaware of his history of crude and sexist comments.

The Prime Minister said: “Toby Young has done exceedingly good work in relation to free schools and that’s what led to him being appointed to the Office for Students.

She added: “He’s now in public office, and as far as I’m concerned if he was to continue to use that sort of language and talk in that sort of way, he would no longer be in public office.”