Anne-Marie Trevelyan said she probably would have “slapped” Stanley Johnson if he inappropriately touched her.
The International trade secretary said incidents such as what is alleged about the prime minister’s father were “something that women have had to tolerate for far too long”.
Labour has urged the Tories to launch an investigation after a senior Conservative MP and a journalist made accusations about Stanley Johnson.
Former minister Caroline Nokes accused the elder Johnson of forcefully smacking her on the backside at the Conservative Party conference in 2003.
Her allegation prompted political journalist Ailbhe Rea to say she was “groped” by Johnson at the party conference in 2019.
Johnson has declined to comment other than to say he has “no recollection of Nokes at all”.
Downing Street declined to comment on the allegations against the “private individual”.
Asked what she would have done in response to the alleged touching, Trevelyan told Sky News: “At the time, I would have probably slapped him.
“But it would’ve been an instinctive response from me and I think Caroline would’ve shown great personal restraint if she quietly moved away.”
Labour leader Keir Starmer praised Nokes’ “bravery” for speaking out, and called for an investigation either by the Tories or the police.
“The allegations are serious and they need to be fully investigated, I don’t think at this stage it’s for me to say what should happen as a result,”Starmer said at a press conference on tackling sleaze in politics.
“But it takes guts and bravery to come forward to make allegations like this. They now need to be fully investigated either by the Conservative Party or by the criminal authorities.”