Sir Michael Fallon has resigned as Defence Secretary following allegations of inappropriate behaviour and acknowledged that "in the past I have fallen below the high standards we require of the armed forces".
The Tory veteran has been caught up in the sexual harassment scandal sweeping Westminster after it emerged he had repeatedly put his hand on talkRADIO presenterJulia Hartley-Brewer's knee during a party conference dinner in 2002.
Hartley-Brewer said she had not regarded the incident as "anything but mildly amusing".
In her reply to Sir Michael's resignation letter, Prime Minister Theresa May said: "I appreciate the characteristically serious manner in which you have considered your position, and the particular example you wish to set to servicemen and women and others."
In a statement, Sir Michael said: "In recent days allegations have been made about MPs' conduct, including my own.
"Many of these have been false, but I realise that in the past I have fallen below the high standards that we require of the armed forces which I have the privilege to represent.
"I have therefore reflected on my position in Government and I am resigning as Defence Secretary.
"It has been a privilege to have served as Defence Secretary for the last three and half years, and I have nothing but admiration for the professionalism, bravery and service of those men and women who keep us safe."
Hartley-Brewer, speaking on Wednesday evening to James Whale on talkRADIO, said: "This is a great shame, but I don't think I am the cause of him resigning. I've always found him to be a fine spokesman for the Government.
"I imagine there are more stories to emerge. This is not about him touching my knee 15 years ago and, if it is, it’s the most absurd resignation of a politician ever."
You can listen to James Whale's interview with Julia Hartley-Brewer above.