Chris Huhne will attempt to carry on as normal today despite allegations threatening to destroy his political career about a speeding fine that may have been blamed on the wrong driver.
Essex Police confirmed that they have been handed information which could lead to a criminal investigation into the Energy Secretary's past.
A spokesman said: "We are aware of allegations regarding a speeding offence in 2003. This information will be passed to officers who will decide on whether an investigation will be launched. We take allegations such as this one extremely seriously and will take action where necessary."
Today, Mr Huhne will meet other ministers to discuss the Government's ambitious plans to cut carbon emissions, which he has finalised after long and tense negotiations with the Treasury. He plans to deliver a Commons statement tomorrow.
His aides continue to deny the allegation which – if it were true – would destroy any hope he has of replacing Nick Clegg as leader of the Liberal Democrats. It could also potentially result in him being sent to prison.
It is alleged that when Mr Huhne was sent a form to fill in about an automatic speeding fine he had incurred in March 2003, he entered another person's name instead of his own, to avoid a driving ban.
He has hired an eminent media lawyer, Charlotte Harris of Mishcon de Reya – who played a leading role in exposing the News of the World phone-hacking scandal – to handle the allegations, which Mr Huhne denies.
Two Sunday newspapers published details yesterday of a private telephone conversation that took place a few weeks ago, in which Mr Huhne discussed the speeding fine. Both The Sunday Times and the Mail on Sunday say they came by the tape legally, and appear to have struck a deal that involves not naming the other person involved in the conversation – evidently someone Mr Huhne knew very well.
Vicky Pryce, the minister's estranged wife, made the original accusation that Mr Huhne had evaded a speeding offence, but did not say who had incurred the fine and penalty points on his behalf. The tape that has been passed to journalists is of a phone call between Mr Huhne and a witness who complained of being under pressure from the media. On the tape, Mr Huhne is reported to have said: "If you don't want anything to get in the paper, don't talk to a journalist."
Later in the conversation, he is heard telling the person on the other end of the line: "There is no way that there is any evidence to this story unless you decide or give some legs to it by saying something. OK?"
The other caller then replies: "I just cannot lie. It's one of the things that always worried me when you made me take them in the first instance." Mr Huhne then objects that it is not "sensible" for him to have "conversations like this over the phone."
At another point in the discussion, which lasted just over 10 minutes, he said: "There's no question of it coming out, because it's simply not true, that's it." This produces the startled reply: "I'm sorry, what? Why are you suddenly saying that?" Mr Huhne then repeats his suggestion that they should meet face to face.
In December 2007, Mr Huhne narrowly lost to Nick Clegg in the contest to be leader of the Liberal Democrats. He is seen as a highly ambitious politician with his eye on Mr Clegg's job, which may have been what motivated his carefully leaked confrontation in Cabinet with the Chancellor, George Osborne, over the conduct of the No2AV campaign earlier this month.
Soon after entering the Cabinet, Mr Huhne's 25-year marriage broke up after he began an affair with his former adviser, Carina Trimingham. He and Ms Pryce have three children.
The Labour MP Simon Danczuk lodged a formal complaint with Essex Police after reading about Mr Huhne and his alleged scheme for averting a speeding fine.
Who's waiting in the wings?
* If Chris Huhne's position in Cabinet were to become untenable but he did not offer to resign, David Cameron could fire him. The Prime Minister has that authority, but would have to take care not to use it in a way that antagonised Liberal Democrats or undermined Nick Clegg.
But Mr Huhne would not be an easy man to replace, because of the complexity of his job. The Foreign Office minister, Jeremy Browne, is said to be the Liberal Democrat the Tories would most like to see in the Cabinet, but not necessarily as Energy Secretary. There might have to be some juggling so that a Tory takes Mr Huhne's place, creating a vacancy for a Liberal Democrat somewhere else.