Claims that energy secretary Chris Huhne asked another person to take penalty points he had incurred for a speeding offence have been denied.
Two Sunday newspapers published the allegations, which relate to a time when he was not an MP.
A spokesman for the Liberal Democrat MP said: "The allegations made against Chris Huhne are simply incorrect.
"These allegations have been made before and have been shown to be un1."
The allegations came to light as Mr Huhne's ex-wife Vicky Pryce spoke about their marriage break-up.
In 2010, Mr Huhne left his wife of 26 years for his lover.
Ms Pryce, a successful economist who quit her job as director general of theDepartment for Business, Innovation and Skills when her husband joined the Cabinet, is now writing a book about her reaction to his cheating and their break-up.
She told The Sunday Times: "Inevitably, being married to a politician means your career comes second to theirs. You have to adapt to that.
"If I had a choice I would still be in the civil service now."
She added: "It had become incredibly difficult for me wandering around Whitehall. On one occasion I had to physically leave the building because my husband was coming into our offices and it could have been embarrassing for everybody."
Copyright © Press Association 2011