Jilted wife Vicky Pryce wanted revenge on cheating husband Chris Huhne for an affair so she betrayed him by an email to the press, it has emerged in court.
Respected economist Pryce revealed that Huhne was driving their car when it was caught on camera speeding. He later claimed that she had been driving at the time.
Huhne resigned from parliament in disgrace after changing his plea to guilty to a charge of perverting the course of justice. He admitted that he had lied for 10 years over the motoring offence which happened in 2003.
Southwark Crown Court heard Pryce wanted "to nail" Huhne by exposing the truth after he cheated on her with assistant Carina Trimingham.
In email exchanges with Sunday Times political editor Isabel Oakeshott, Pryce said: "I definitely want to nail him. More than ever, I would love to do it soon."
The pair discussed how to get maximum publicity for Huhne's crime. Oakeshott suggested a two-part splash across the pages of the paper to inflict "maximum and perhaps fatal damage on Chris if you are prepared to be open". Oakeshott said it would result in "bringing Chris down without damaging your own reputation in the process".
Pryce used a secret recorder supplied by the Rupert Murdoch-owned title to try to get Huhne to admit the deception on tape.
She is standing trial for perverting the course of justice by taking the penalty points for speeding in place of her husband.
She denies the charge and claimed he made her do it. She is using a little-known defence available only to women called "marital coercion".
Andrew Edis QC, prosecuting, told the jury that Huhne could not have committed the crime without Pryce colluding in a conspiracy to trick police.
"Focus not on whether she was persuaded but whether she was in a situation where she had a choice," he said.
He said details of the motoring offence came to light only after Pryce discovered her husband, with whom she had two children, was cheating on her with another woman.
"She was not only distressed but extremely angry and wanted some revenge and her revenge was to pass the story about the 2003 crime to the newspapers so that it would be published in the hope that would destroy her husband's career," Edis said.
The case continues.