Andrea Leadsom did not ask the Prime Minister to sack Michael Fallon, Downing Street sources said following reports the Commons Leader passed a dossier of claims about her former Cabinet colleague to Number 10.
Mr Fallon quit as defence secretary after admitting his behaviour had "fallen below the high standards required" in the role, becoming the first ministerial casualty of the Westminster sleaze row.
But sources close to the Tory MP said he "fundamentally denied" claims he made a crude joke to the Commons leader.
A Downing Street source said: "The Leader of the House did not and had not asked the Prime Minister to consider the position of Sir Michael while he was defence secretary."
The Sun reported that Mrs Leadsom accused Mr Fallon of a string of inappropriate remarks when they were both members of the Commons Treasury Select Committee
According to the newspaper, the Commons Leader demanded to see the Prime Minister's chief of staff Gavin Barwell on Tuesday evening - with Mr Fallon's resignation following on Wednesday night.