EASTLEIGH MP Chris Huhne tonight faces jail and the humiliating end to his political career after dramatically admitting lying to avoid a speeding penalty.
After nearly two years proclaiming his innocence and fighting to have the case dropped, the former energy secretary pleaded guilty on the eve of his trial to making ex-wife Vicky Pryce accept points on his behalf.
The 58-year-old immediately announced he was standing down from parliament - sparking a by-election in marginal Eastleigh that could test coalition relations to the limit - and voluntarily removing himself from the Privy Council.
Liberal Democrat leader Nick Clegg said he was ''shocked and saddened'' by the news, but added that Huhne was doing the right thing by quitting the Commons. Huhne's legal team had made two previous attempts to get the case dismissed or suspended, and as recently as last week he told the court he was not guilty of perverting the course of justice.
However, when asked again at London's Southwark Crown Court this morning, he clearly replied: ''Guilty.''
Mr Justice Sweeney granted Huhne unconditional bail, but warned him he should have ''no illusions whatsoever as to the sort of sentence that you are likely to receive''.
Perverting the course of justice carries a maximum life prison term - but the average is around 10 months.
PR adviser Carina Trimingham was in the public gallery to watch as Huhne made his confession.
The emergence of their relationship in September 2010 ended his marriage to 60-year-old Pryce, and the speeding allegations leaked out soon afterwards.
Pryce continues to deny perverting the course of justice over the speeding fine in 2003, and her trial is due to begin tomorrow.
Making a statement outside the court afterwards, the Lib Dem said: ''Having taken responsibility for something that happened 10 years ago, the only proper course of action for me is to resign my Eastleigh seat in Parliament, which I will do very shortly.''
A party spokesman said Huhne had made clear he intended voluntarily to remove himself from the privy council - giving up the Right Honourable title granted to senior politicians.
However, there is no sign that he will hand back the £17,000 severance payment he received on quitting the Cabinet last February.
The developments caused shock at Westminster, where Huhne had been telling friends recently that he expected to be cleared.
The MP was only narrowly beaten by Mr Clegg for the party leadership in 2007, and until his tumultuous downfall he was still regarded by many as the Deputy Prime Minister's natural successor.
Giving his reaction, Mr Clegg said: ''This is obviously an extremely serious matter and it's essential that the legal process is now allowed to run its course.
''I am shocked and saddened by what has happened, but I believe that Chris Huhne has taken the right decision in resigning as an MP.''
Labour MP Simon Danczuk, whose complaint sparked the investigation by Essex Police, said: ''It looks like Chris Huhne tried to engineer a cover-up that he couldn't sustain, and that is presumably why he's pleaded guilty today.
''None of us are above the law, including ministers, but I do have some sympathy for Chris Huhne in that I wouldn't have wished his political career to be ruined in this way.''
Alongside the potential loss of his freedom and political career, the guilty plea also exposed evidence of the bitter rifts created at the heart of the Huhne family.
In text message exchanges dating from 2010 and 2011 that were read out in court, Huhne's son Peter branded him ''disgusting'' and ''the most ghastly man I have ever known''.
Ignoring entreaties from his father, Peter - in his late teens at the time - wrote: ''We all know that you were driving and you put pressure on mum. Accept it or face the consequences.''
Huhne's exit raises the prospect of a major coalition clash in the by-election for his Eastleigh seat.
The Lib Dem MP had a majority of 3,800 at the 2010 general election, but it is viewed as a key target seat for the Conservatives if they are to get an overall majority in 2015.
There is also the prospect of UK Independence Party (UKIP) leader Nigel Farage making another run for Parliament. He previously stood unsuccessfully in the seat.
Party sources said UKIP would be fielding a candidate in Eastleigh and Mr Farage would consider the situation, adding that the constituency was ''very close to his heart''.
The Liberal Democrat leader of Eastleigh Borough Council, Keith House, he was ''very sad'' about Huhne's resignation, saying he had been a ''hard-working MP''.
''The Liberal Democrats have a solid base in Eastleigh. They have won every election here for eight years and we will go forward,'' he added.
The Tory candidate is likely to be business consultant Maria Hutchings, 51, who famously assailed Tony Blair over care and education for her autistic son during the 2005 general election campaign.
A local party source said: ''Maria is popular in the local party and has already been campaigning in Eastleigh.''
A source close to Labour leader Ed Miliband said: ''We recognise this is an uphill struggle, but as a one-nation party we fight in every seat and campaign in every part of the country.
''We intend to campaign hard against both coalition parties.''
It is understood that Eastleigh is 258th on Labour's target list.
We cannot allow comments for legal reasons, as a Vicky Pryce's trial begins tomorrow.