The Home Secretary said it was right the former Cabinet minister resigned as defence secretary earlier this week over his previous behaviour.
Sir Michael’s decision to stand down was cast in new light on Sunday as Jane Merrick accused him of lunging at her and trying to kiss her on the lips when she was a junior reporter.
She alleged the incident took place following a lunch when she worked for the Daily Mail in 2003.
Speaking on Sky News’ Sunday with Niall Paterson, Ms Rudd said the incident was “completely disgusting, absolutely wrong and it is right that he has stepped down”.
She added: “He’s made his statement about what he believes was the right thing to do.
“As a result of that and other disclosed situations, allegations, some of which are turning out to be correct, some of which we don’t know, there will be full change at Westminster.”
Writing in The Observer newspaper, Ms Merrick said after the incident with Sir Michael she had “shrank away in horror” and “ran off” to her office in Parliament’s Press Gallery.
She said: “I felt humiliated and ashamed.
“Was I even guilty that maybe I led him on in some way by drinking with him?,” she asked.
“After years of having drinks with so many other MPs who have not acted inappropriately towards me, I know I was not.”
A friend of Sir Michael has told Sky News the former defence secretary “realises this kind of incident was unacceptable, which is why he resigned”.
In stepping down, Sir Michael said his personal conduct had “fallen below the high standards we require of the armed forces”.
It is the third allegation made against him within a week, after he apologised for putting his hand on journalist Julia Hartley-Brewer’s knee during a Conservative party conference 15 years ago; and he was accused of making lewd remarks – which he denies – to Cabinet colleague Andrea Leadsom.
Ms Merrick said she decided to name Sir Michael, having previously declined to do so, after he “denied some allegations, and minimised others as somehow acceptable because they date from another time”.
“His lack of contrition has made me change my mind,” she said.
Meanwhile, the Westminster sex pest scandal, which has already led to a series of suspensions and investigations, showed no sign of abating with fresh allegations being made against MPs.
In a speech to party activists on Sunday, Labour leader Jeremy Corbyn criticised Westminster’s “warped and degrading” culture of sexual harassment.
He said: “Faced with the ongoing revelations about sexual harassment, we must make this a turning point and a moment of real change.
“We must say ‘no more’. We must no longer allow women, or anyone else for that matter, to be abused in the workplace or anywhere else.”
Mr Corbyn has faced criticism for appointing now suspended Labour MP Kelvin Hopkins to the shadow cabinet after allegations of inappropriate behaviour had been made against him.
Mr Hopkins has “categorically” denied claims, which are now being investigated by Labour.