But when asked again this morning, he clearly stated: “Guilty.”

PR adviser Carina Trimingham was in the public gallery to watch as Huhne made the admission. The emergence of their relationship in September 2010 ended his marriage to 60-year-old Pryce, and the speeding allegations leaked out soon afterwards.

Perverting the course of justice carries a maximum sentence of life - but the average is around 10 months.

Under Commons rules, MPs are only forced to step down if they receive custodial terms of more than 12 months, but realistically Huhne’s departure was regarded as inevitable.

Liberal Democrat leader of Eastleigh Borough Council Keith House said of the MP's resignation: “It is very, very sad to learn of Chris's resignation. He has been a hard-working MP for Eastleigh for the last eight years and has built up a reputation for hard work, both locally and nationally.

“The Liberal Democrats have a solid base in Eastleigh. They have won every election here for eight years and we will go forward.

“I will be involved in the selection of a new candidate but I am not looking to be the candidate.”

Prime Minister David Cameron's official spokesman declined to comment on the former minister's resignation, saying only: “It is a matter for Mr Huhne.''