Liam Fox suffered another setback last night when it emerged that he faces a second inquiry into links with his friend and self-styled adviser Adam Werritty.
Shortly after the former Defence Secretary launched an attack in the Commons on the media in his resignation statement, John Lyon, the Parliamentary Standards Commissioner, announced he will investigate whether Mr Fox broke Commons rules by allowing Mr Werritty to stay rent-free in his flat, for which Mr Fox received the MPs' second-homes allowance.
Mr Lyon's decision to launch a full investigation is also a blow for David Cameron, who had hoped a line had been drawn under the affair.
Mr Fox accused some newspapers of displaying "personal vindictiveness – even hatred" during the "media frenzy" which forced him to quit his Cabinet post last Friday. Some MPs pointed out that he would not have been forced to resign unless the media had investigated Mr Werritty's role.
Sir George Young, the Leader of the Commons, told MPs in a statement yesterday that Ursula Brennan, Permanent Secretary at the Ministry of Defence, was wrong not to have reported her concerns about Mr Werritty's role to Sir Gus O'Donnell, the Cabinet Secretary. He suggested the affair might have been avoided if she had. Kevan Jones, a Labour defence spokesman, said: "Liam Fox is not a media victim. Investigative journalism revealed the facts he chose to omit from his public statements."
In an otherwise contrite resignation speech, Mr Fox said he was "very sorry" for his actions and accepted Sir Gus's inquiry verdict that he had broken the ministerial code.