Britain's most senior civil servant will tell Chris Huhne he has to resign if he is charged with a criminal cover-up, The Independent has been told.
The Cabinet Secretary, Sir Jeremy Heywood, is believed to have concluded that the Energy Secretary would have no choice but to stand down or be sacked if the Crown Prosecution Service presses charges against him.
Mr Huhne, 57, is waiting to hear whether he faces prosecution for perverting the course of justice following claims that he made his ex-wife Vicky Pryce take penalty points for speeding on the M11 in 2003.
The Energy Secretary, who vociferously protests his innocence, has sought to argue that he would not necessarily have to stand down even if he faces criminal prosecution on the grounds that he would be innocent until proven guilty.
But sources close to Sir Jeremy have made clear that this would be unacceptable as it would undermine faith in the ministerial code. The Cabinet Secretary also believes Mr Huhne would not have time to conduct his ministerial duties if he is also fighting a court case.
A senior Government source said: "The Cabinet Secretary will take the view that the Secretary of State for Energy should discharge his position to take time out to concern himself with the circumstances of the case."
Mr Huhne's fate ultimately lies in the hands of the Prime Minister, David Cameron. But Mr Cameron would consult Mr Huhne's party leader Nick Clegg and the Cabinet Secretary, who is the senior adviser to both men.
Sir Jeremy's view would be crucial since he will be asked whether he thinks Mr Huhne has breached the Ministerial Code of Conduct.
The code makes clear that there is an "overarching duty on Ministers to comply with the law including international law and treaty obligations and to uphold the administration of justice and to protect the integrity of public life".
Mr Clegg made clear last weekend that he thinks it would be difficult for Mr Huhne to stay in his job. He told the BBC's Andrew Marr that it would be a "very serious issue" if the CPS charged Mr Huhne.
By contrast, allies of Mr Huhne have pointed out that the ministerial code does not require ministers to step down automatically if they were a defendant in a criminal case – only that government lawyers must be consulted. The way was cleared for a swift ruling on the case after The Sunday Times dropped a High Court challenge over emails relating to the allegations earlier this month.Reuse content