Pressure mounted on Chris Huhne last night with a flurry of fresh allegations over his penalty points saga, including the claim that he accepts that he may have been driving his car on the day it was clocked speeding eight years ago.
The embattled Energy Secretary is expected to tell police he "cannot be sure" he was not behind the wheel when it was caught exceeding the speed limit in March 2003, according to a report in The Sunday Times.
The paper quoted a member of Mr Huhne's camp saying that he could not remember his movements on the day in question. The source added: "He hasn't got a diary about whether he drove or not."
The concession follows weeks of flat denials that Mr Huhne pressurised his wife, Vicky Pryce, into accepting the three-point penalty so he could escape a driving ban. Observers pointed out that, if the minister is interviewed this week by police under caution, the "can't remember" position would be more easily defensible in law if the case ever went to court.
The development came as a copy of Ms Pryce's driving licence was published, showing that she was given a three-point penalty for an offence committed on March 12, 2003 – the day Mr Huhne, then an MEP, is alleged to have been caught speeding while driving back from Stansted airport in Essex.
It has already been established that on that same day Ms Pryce had attended a conference and dinner until after 10pm in central London, at least an hour's drive from Stansted. Records show that Mr Huhne, who was an MEP at the time, was in the European Parliament in Strasbourg until the afternoon of March 12. If he followed his normal routine, he would have then boarded a Ryanair flight to Stansted, which landed at 10.23pm.
The appearance of the driving licence is the first documentary proof that a speeding offence was committed on the day in question – and that Ms Pryce took the punishment.
The couple were married for 26 years before Mr Huhne moved out of the family home last June, after it was disclosed that he had been having an affair. Relations between the couple have deteriorated rapidly over recent months, to the point where the allegations over the speeding penalty have put Mr Huhne's Cabinet career in jeopardy.
It was also reported last night that Ms Pryce is expected to tell police that a female confidante of her husband also took points for him on her driving licence. The Sunday Telegraph said Ms Pryce, who will be interviewed by police this week, claims Mr Huhne evaded points for speeding on more than one occasion.
"Vicky has been telling people she is not the only one to take points and that Chris had got someone else to do it before her," one source told the newspaper. "She has said she will do whatever is necessary and appropriate to help the police investigation and that means telling them everything she knows."
Essex police have confirmed that they have begun a formal investigation into allegations that Mr Huhne persuaded someone else to take penalty points for speeding. They are expected to interview him in the coming days.
Amid growing unease at the highest levels in government that the coalition is becoming tainted by ministerial incompetence, those closest to the Energy Secretary admit the stakes could not be higher.
"For Chris, it is shit or bust," said one close family friend. "It is not in his nature to do the humble thing and go quietly. He has staked everything on this, and now he has reached the Cabinet he will not go quietly."
When asked earlier if he was considering resigning, Mr Huhne replied: "No, thank you very much."
Mark Pack, from the grassroots website Liberal Democrat Voice, said: "The allegations are very serious but, given the lack of public evidence so far, members are rightly waiting to see what the police conclude."
Mr Huhne's marriage to Ms Pryce, ended after he admitted to a relationship with an aide, Carina Trimingham, then in a civil partnership. Ms Pryce's lawyer said reports that Mr Huhne had had another affair before he left her had "come as an additional shock to her and the family".
And yesterday the Electoral Commission confirmed that it was examining a complaint over his general election expenses. Two former Lib Dem councillors in his Eastleigh constituency allege Mr Huhne made a "false declaration" of his expenses. Mr Huhne said he had "no reason to believe there are any irregularities".
Others on the ropes...
The Justice Secretary sparked a political storm after drawing a distinction between "serious, proper rapes" and others while discussing his plan to halve jail sentences for early guilty pleas. Ed Miliband, the Labour leader, called for him to be sacked – guaranteeing his survival. But the Tories are fearful of looking weak on crime.
Downing Street was so fearful that the Health Secretary would quit over attacks on his NHS reform plans that two trusted aides were sent to bolster his weak team at the Department of Health. The battle is not over yet, with a major rewrite of the plans demanded by Lib Dems – dubbed "yellow bastards" by Tory backbenchers.
Given the frequency with which his letters criticising coalition policy are leaked, the Defence Secretary needs to change his postman. His swipes at cuts to the armed forces over overseas aid budgets have angered No 10, which believes his back-bench support is overstated.