Chris Huhne's ex-wife Vicky Pryce revealed the fact she had taken his speeding points in a bid to get revenge after he left her for another woman, a court heard today.

Former energy secretary Huhne was clocked speeding in March 2003 and persuaded his then wife Pryce to take his points so he could avoid losing his licence.

Huhne and Pryce were both charged last year with perverting the course of justice over the offence and were due to stand trial together.

But the former Cabinet minister dramatically changed his plea yesterday, admitting the offence and resigning as an MP.

His ex-wife still denies the charge, saying she was coerced into taking the points and is standing trial alone.

Opening the case at Southwark Crown Court today, prosecutor Andrew Edis QC said the points-swapping only came to light in 2010/2011 when Pryce told several newspapers in a bid to ruin her former husband's career.

Mr Edis told the jury of eight women and four men: "It became public because Ms Pryce told a newspaper, actually more than one.

"And she told the newspapers because by then, 2010/11, she had learned that Mr Huhne had been having an affair with somebody else and he, Mr Huhne, had told her, in a way which you may learn something about, that he did not want to be with Ms Pryce any more, it was over."

He said the ending of a long marriage in circumstances like that would undoubtedly be "a cause of immense distress to any wife, or husband come to that".

"And there is no doubt at all that Ms Pryce was distressed.

"But there is also no doubt at all that she was not only distressed but extremely angry and she wanted some revenge.

"And her revenge was in the end to pass the story about the 2003 crime to the newspapers so that it would be published in the end, that it would destroy her husband's career."

The jury was told of an email exchange dating from March 1 2011 between Pryce and Sunday Times journalist Isabel Oakeshott in which they discussed how to publicise the points affair.

Ms Oakeshott suggested they do a number of pieces including news features and a story at the front of the paper, writing: "This is what I strongly recommend you do, given your dual objectives of bringing Chris down... without seriously damaging your own reputation in the process."

In a later email she warned Pryce of the danger of facing criminal proceedings if she did reveal that she took his penalty points, and that the newspaper was discussing the issue.

Pryce wrote: "I would need some reassurance that it would bring Chris down."

Later she added: "I have no doubt, as I really want to nail him. More than ever actually, and I would love to do it soon."

Ms Oakeshott later replied: "The bottom line is that this story will bring Chris down if you are prepared to go on the record, with the minor risk this carries.

"I think you can make yourself out to be very much the honourable one, saying it has very much been on your conscience ever since, saying you knew it was wrong but you were bullied into it."

Mr Edis said the jury will hear four phone calls between Pryce and Huhne that were recorded with the help of the Sunday Times in a "set up" to get him to admit the points swapping and prove the story.

"Isabel Oakeshott is trying to get the story to stand up so it can go in the newspaper so nobody gets sued for libel or whatever," he said.

The plan was that Pryce would phone her ex-husband, get him to admit the allegation, and it would all be recorded as evidence.

"It is, in fact, a set up," Mr Edis told the court.

"Mr Huhne did not fall for it. He denied repeatedly the suggestion that he had asked her to take any points and said that it was all ridiculous.

"We know from what happened yesterday that when he was denying it he was doing that for the benefit, not of the truth, but for whoever might be listening to the telephone call."

He said Huhne was obviously aware of what was going on, and was being "manipulative" but said Pryce was also being manipulative by trying to get him to confess.

"You might come to the conclusion that these telephone calls are two manipulative people trying unsuccessfully to manipulate each other."

He said the calls would show Pryce was "angry, persistent" and "assertive", saying: "And of course the situation is wholly different from what it was in 2003.

"We know that the marriage is at an end, it's come to an end in horrible circumstances, and the ties of loyalty no longer exist."

At the start of the hearing, Mr Edis told jurors Pryce had agreed to "play ball" and take the points for Huhne when he was caught in 2003.

But he said she would now use a special legal defence available only to wives, saying that she was coerced by him into taking them.

Of the points swapping, he said: "It is an offence which actually really can only be committed by two people working together to achieve it and that's what the prosecution say has happened here.

"These basic circumstances are all going to be agreed.

"Ms Pryce agrees that she was not driving the car and she agrees that the form was filled with her, I am going to say consent.

"And she agrees that she knew it was going to happen."

But he added: "Ms Pryce says that she filled in the form and took the points at a time when she was married to Mr Huhne.

"She no longer is, they have subsequently had a divorce, and the law says that if a wife commits an offence in the presence of her husband and because he has coerced her into doing it, then she has a defence."

Mr Edis told jurors that although it had not gone smoothly throughout, ultimately Pryce's plan had worked.

"Mr Huhne was charged, he did resign, yesterday he pleaded guilty, he is not a Cabinet minister any more. So the plan worked," he said.

He said the jury would have to decide whether Pryce, an economist and senior civil servant, was "weak-minded" and forced into accepting the points by Huhne or was a "strong-minded and manipulative" woman acting of her own free will.

"Focus not on whether she was persuaded but whether she was in a situation where she had a choice," he said.

He added: "Her revenge in the end was to pass the story of the 2003 points to the newspaper so they would publish it and destroy his political career.

"It was Pryce's plan that she would get her revenge by putting an end to all that.

"She would publish what she and he had done together without complaint in 2003 so she would get her revenge for the undoubtedly very bad way he had treated her."

The jury was played four calls Pryce made to Huhne around April 2011, which were recorded with Ms Oakeshott's help in a bid to get some proof for the story.

During the calls, Pryce tries to get her former husband to admit that she took his points in 2003.

The economist constantly asks Huhne to confirm that she received the points, but he staunchly denies it, advising her not to speak to journalists.

At one point he tells her: "Can I suggest, if you want to stop journalists door-stepping you, you stop telling ridiculous stories to the press."

She denies having anything to do with it, claiming that someone else was the source of the story.

In several exchanges, Pryce, at times angry and swearing, demands Huhne admit she took his speeding points, with comments like "You know full well that I took your points", while her ex-husband continually denies it.

She also denies having anything to do with the rumours circulating Fleet Street, saying: "Why would I tell anyone about me taking your points? It's not in my interests. Are you a moron?"

Huhne - apparently cautious about discussing the issue with Pryce on the phone - tells her so and says they can meet in person.

He repeatedly warns her not to talk to journalists, and says the story will not appear if they do not "stand it up".

Pryce makes several digs about Huhne's new partner, Carina Trimingham, describing her as "your f****** man".

She claims Huhne's "entire family" knew she had taken her points, but her ex accused her of "maliciously briefing the press" to ruin his political career.

In the four conversations, Pryce tells Huhne she does not want to "perjure" herself by denying the story, saying: "It's one of the things that's always worried me when you made me take them in the first instance."

The case at Southwark Crown Court was adjourned to 10am on Thursday.

* Huhne formally stood down as an MP today by accepting the post of Steward and Bailiff of the Chiltern Hundreds.

The archaic title is used as a device to get round the Westminster rule that MPs cannot resign their seats. Appointment to the Chiltern Hundreds means an MP notionally becomes a salaried agent of the monarch and his or her seat is therefore revoked. speeding points