Chris Huhne's ex-wife 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.
Vicky Price described her desire to "bring Chris down" and "nail him" in email exchanges with a journalist.
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 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."
Pryce, 60, of Crescent Grove, Clapham, denies tending and intending to pervert the course of justice between March 12 and May 21, 2003, by falsely telling authorities that she was driving the car.