Chris Huhne has always liked to drive in the fast lane. Clever, rich, ambitious, he was one of the relatively few MPs who had carved out a successful career before he entered politics. Incoming MPs are normally expected to move forward slowly during their first few years in parliament, as they learn the unwritten rules of the road. But Huhne acted as if the speed limits didn't apply to him.
Even his enemies acknowledge that Chris Huhne is highly able, but there is another quality to him which means that he has fewer real friends than he needs in a time of crisis.
He is a long way from being the Tory party's favourite Cabinet minister after his combative role during this year's AV referendum, when he accused the Tory chairman, Baroness Warsi, of running an "increasingly Goebbels-like campaign" and went for George Osborne during a Cabinet meeting over the No campaign's attacks on Nick Clegg, making sure the story of the confrontation leaked out.
We have it on very good authority that Huhne's ambition has at times made him guilty of "opportunism". Nick Clegg said so, on the internet, when he and Huhne were new MPs.
Huhne's supporters subsequently returned the compliment, during the 2007 party leadership contest, by producing a leaflet with the damning headline "Calamity Clegg". When challenged about it, Huhne said it had been produced without his knowledge.
The two rivals had been in the Commons only eight months when the Lib Dems were thrown into crisis by the abrupt resignation of their leader, Charles Kennedy, who had a drink problem. It was assumed that the resulting election would be a contest between two old stagers – Ming Campbell, representing the party establishment, and Simon Hughes, the voice of the rank and file.
Campbell's team believed, rightly or wrongly, that they had a promise of support from Chris Huhne who, in 2004, had been a contributor to a publication famous in Westminster circles as the Orange Book. Its authors hoped to do for the Liberal Democrats what Tony Blair had done for Labour. Almost all the Orange Book group, including three future Cabinet ministers – Nick Clegg, Vince Cable and David Laws – rallied behind Campbell. Only Huhne struck out alone, running as a candidate despite having been an MP for such a short time.
He campaigned so cleverly that, having begun as what the press called "the rank outsider" or the "unknown Mr Huhne", he overtook Simon Hughes, whose campaign was crippled by a tabloid story about his private life, and gave Ming Campbell a serious fright, collecting 21,628 votes, only 8,000 short of victory.
Though his success earned him respect as organiser and campaigner, it did not make him popular. During the campaign, Clegg warned party members not to back a man who "in making various headline-grabbing announcements" had opened himself up to "accusations of opportunism".
One senior figure who backed Clegg thinks that the word opportunism was well chosen. He said of Huhne: "He's very bright, but arrogant and over-self-confident. He's a very clever guy who knows he's very clever. He is very good on the chicken circuit. I have seen him charm party members, and they love him.
"But one minute he was a champion of the Orange Book, then he was the voice of the rank and file. It looks opportunist."
One of the secrets of Huhne's success was his 25-year marriage to Vicky Pryce. When they wed, in 1984, he was an economics journalist with a reputation for pushing a story as far as the truth would allow. Her income as an economist and high-flying civil servant gave him the financial independence to go into business on his own in the city, and become a millionaire.
He got his big break in politics in 1999 as an MEP, and then scraped into the Commons in 2005, in Eastleigh, where the Liberal Democrat majority dropped to only 568.
When Ming Campbell's brief tenure as leader ended with his resignation, Huhne put himself forward again, and very nearly won. The final tally was Clegg 20,988 votes, Huhne 20,477. It is an open secret that Huhne might be the Deputy Prime Minister today if 1,300 postal votes had not come in too late after being caught up in the Christmas post.
But Huhne knuckled under, having wisely decided that it would do neither himself nor the party any good if he was seen to be trying to undermine the new leader. His loyalty was rewarded last May when, with his wife at his side, he was re-elected MP for Eastleigh with an increased majority.
In the following days he was a strong advocate for the coalition, but he had hardly settled down behind his new desk at the Department of Energy when he committed a shocking betrayal, abandoning the woman who had done so much for him to take up with his bisexual former spin doctor, Carina Trimingham, who was 13 years younger than his wife.
Vicky Pryce was very popular within the Liberal Democrat party, as was demonstrated when she turned up to the autumn conference after the public split with her husband. Vince Cable, who was her political boss when she was chief economist at the Business Department, stepped down from the platform to give her a welcoming kiss.
Her revenge has been to leak the story of how she once allegedly accepted Huhne's penalty points when he was seemingly rushing from one place to another without considering the consequences of too great haste. When he denied the story, she backed it up with a recording of a telephone conversation in which he was urging her to keep quiet about what happened.
Today, Huhne's career is on a knife edge, but there are those who still believe he can pull through and keep his career on track. The former Lib Dem MP Evan Harris, who backed Huhne in 2007, believes he could yet be a future party leader. "It's ridiculous to call for Chris's resignation when there isn't even an investigation," he said. "If the story's not true, it's not true and there's nothing to it."
How not to play politics
Ming believed he had a pledge of support from Chris Huhne in the 2006 party leadership election, and was not pleased when the younger man ran against him, coming a very good second. Ming's revenge was to promote Nick Clegg to a more senior position than Huhne on the Lib Dem front bench.
Confronted with a leaflet produced by his leadership campaign, headed "Calamity Clegg", Huhne denied any knowledge of it, but his apology was hardly fulsome. He said: "I don't support describing anyone in the party as a calamity, but we've seen a series of flip-flops from Nick."
Chris Huhne's patience wore out after the Tory co-chairman wrote a piece in The Sun claiming that reform of the voting system would pander to the likes of the BNP. "This is another example of the increasingly Goebbels-like campaign from the anti-AV people," he said.
Ignoring the normal rule that cabinet meetings are about government policy, not party politics, Huhne directly challenged David Cameron and George Osborne about No2AV's tactics. "This is the Cabinet, not some sub-Jeremy Paxman interview," Osborne snapped.