Mr Young was forced to explain why he had posted messages commenting on the appearance of women’s breasts, described gay singer George Michael as “queer as a coot” and written a story about dressing up as a lesbian in which he referred to gay women as “hardcore dykes”.
The Prime Minister admitted she was “not at all impressed” by the right-wing journalist’s previous remarks but suggested she would not reverse his appointment to the Office for Students board.
Speaking to the BBC’s Andrew Marr Show, she 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.
“When he was appointed I was not aware of these comments that he had made. Frankly I’m not at all impressed by those comments.”
She warned Mr Young she will sack him if he continues to post offensive messages, saying: “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.
“He’s apologised but if he continues to talk and use this sort of language, then he will no longer be in public office.”
In comes after a Downing Street source said Ms May considered the tweets to be “distasteful”.
Opponents said Ms May was wrong to stand by Mr Young.
Vince Cable, leader of the Liberal Democrats, said: “Theresa May stood by her new universities regulator when she should be firing him – his appointment is completely unsustainable. This is a man who has a record of misogyny and backs eugenics, screening out people of supposedly low intelligence.
“This shows bad judgement and, as the Prime Minister effectively admitted, a lack of due diligence. It seems all you need to survive is be a friend of Boris Johnson.”
In addition to his comments about women and gay people, Mr Young was also revealed to have tweeted a joke about deriving sexual pleasure from watching a Comic Relief television clip about Kenyan children living in extreme poverty.
When one Twitter user wrote in 2009 that she had “gone through five boxes of Kleenex” while watching the harrowing clip, Mr Young replied: “Me Too, I havn’t [sic] w***** so much in ages.”
The journalist, who has also founded several free schools, has since deleted almost 50,000 tweets from his account in an apparent attempt to stop further damaging revelations.
Labour urged the Prime Minister to sack Mr Young after the offensive posts came to light.
Dawn Butler, the party’s Shadow Equalities Minister, told The Independent: “If she fails to rethink this appointment, the message Theresa May is sending to students is that under the Tories, misogyny and homophobia will not just be tolerated but rewarded.”
In response, Mr Young said: “I’m neither misogynistic nor homophobic. I’m a strong supporter of both women’s rights and LGBT rights.”
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