Theresa May is set to appoint a new defence secretary after Sir Michael Fallon became the first ministerial head to roll in the Westminster sleaze scandal.
Sir Michael quit after admitting his behaviour had “fallen below the high standards required” in the role and acknowledging that what might have been acceptable in the past was no longer appropriate.
The resignation leaves the Prime Minister facing a reshuffle and deprives her of one of her most experienced and trusted colleagues.
The move comes as Scottish Conservative leader Ruth Davidson said there needed to be a “house clearing”.
Speaking at a political awards ceremony, Ms Davidson said: “Just because we have a woman in Number 10, at the top of the tree in Plaid Cymru, in the Scottish Conservatives, in the SNP, in the DUP, doesn’t mean that sexism and misogyny are somehow resigned to the dustbin of history when it comes to politics.
“Nor, when we look at some of the house clearing that … needs to happen in the next few weeks, months and years ahead, are we going to say that we didn’t need some pretty big shovels for the Augean stable.
(Prime Minister’s Office/PA)
“The house clearing that is about to happen needs to happen and we can never go back to where we were before.”
Sir Michael’s shock announcement came after it emerged he had repeatedly put his hand on a journalist’s knee at a dinner in 2002.
His name also appeared on an unverified list of sexual misconduct allegations circulating in Westminster.
(Prime Minister’s Office/PA)
In his resignation letter to the Prime Minister, Sir Michael said: “A number of allegations have surfaced about MPs in recent days, including some about my previous conduct.
“Many of these have been false but I accept that in the past I have fallen below the high standards that we require of the armed forces that I have the honour to represent.”
Asked whether he was worried that there would be further revelations about his behaviour, Sir Michael told the BBC: “The culture has changed over the years, what might have been acceptable 15, 10 years ago is clearly not acceptable now.
“Parliament now has to look at itself and the Prime Minister has made very clear that conduct needs to be improved and we need to protect the staff of Westminster against any particular allegations of harassment.”
The 2002 Tory party conference incident involved radio host Julia Hartley-Brewer, who previously said she regarded it “mildly amusing”.
She reacted with shock to Sir Michael’s announcement, writing on Twitter “bloody hell” before adding “I doubt my knee was the reason” for his resignation.
When allegations of sexual misconduct first began circulating last week, ministers were warned by Downing Street that “serious action” would be taken by Mrs May where necessary.
Sir Michael’s resignation will fuel speculation that other ministers could also be forced out as a result of the scandal.