Boris Johnson’s past comments about “tank-topped bumboys” make him “unfit” to be foreign secretary, a senior Labour MP has said.

Johnson’s comments about gay people and women made while working as a journalist were highlighted by Business Insider after he defended the appointment of Toby Young to the new universities regulator.

The government’s decision to hand Young the job was met with disbelief by opposition MPs who said his views about women, LGBT people and the disabled disqualified him.

Johnson, who used to edit The Spectator for which Young has been a regular contributor, condemned the “ridiculous outcry” over his former employee.

Writing in the Spectator in 2000, Johnson attacked “Labour’s appalling agenda, encouraging the teaching of homosexuality in schools, and all the rest of it”.

And in a 1998 Daily Telegraph column, he said the resignation of Peter Mandelson from the then Labour government would cause “tank-topped bumboys” to “blub”.

Dawn Butler, Labour’s Shadow Minister for Women and Equalities, said Johnson should not keep his job in Cabinet.

“Boris Johnson’s track record and his defence of Toby Young, whose misogynistic and homophobic views he published as editor of the Spectator magazine, surely make him unfit to be the UK’s most senior diplomat,” she said.

Young, who has deleted thousands of tweets following the outcry over his own comments, appeared to question the origin of Johnson’s remark when discussing a piece by Times columnist Matthew Parris.

Among the tweets deleted by Young, include the suggestion there “should be an award for Best Baps” for women and that he had his “dick up her arse”.

In 2012, he wrote for The Spectator about the “ghastly” need for schools to be inclusive by having things like wheelchair ramps.

In 2011, he wrote a blog for The Spectator, condemning a school in Stoke Newingtonfor celebrating LGBT rights with a week of lessons focussed on the issue.

“The very idea that a group of 12-year-old schoolchildren would be dragooned into ‘creating banners and other materials’ to promote LGBT week is preposterous,” he said.

In 2000, Young wrote for men’s magazine GQ about disguising himself as a lesbian, including by putting on a wig, and trying to infiltrate gay bars in New York to kiss other women, some of whom he referred to as “hard-core dykes”.