Kent frontbencher Sir Michael Fallon has admitted touching a journalist’s knee, as allegations of alleged misbehaviour among MPs surface, according to a national newspaper.

The defence secretary admitted inappropriately touching the female reporter, as a dossier claiming to highlight parliamentary sex pests comes to light.

The Sun claimed Sir Michael has come forward to admit he is the minister referred to by talkRADIO presenter Julia Hartley-Brewer, whhen she said she threatened to punch someone for repeatedly putting their hand on her knee.

But the newspaper said the Sevenoaks MP had apologised at the time, and both considered the matter closed.

The alleged knee touching was said to have occurred at a Conservative party conference.

The paper reported her as saying: “I calmly and politely explained to him that, if he did it again, I would punch him in the face.

“He withdrew his hand and that was the end of the matter.”

This evening she tweeted that the incident happened in 2002, and “no-one was remotely upset or distressed by it”.

The revelations come as a dossier claims to name six cabinet ministers as alleged sex pests.