Vicky Pryce planned to "nail" her ex-husband Chris Huhne for leaving her for another woman by telling the press the truth about his M11 joyride, Southwark Crown Court heard today.
Jurors were read emails between Ms Pryce, an economist, and Sunday Times political editor Isabel Oakeshott in which they discussed how the story could be published and end the former Lib Dem energy secretary's career.
Mr Huhne pleaded guilty to perverting the course of justice on Monday and quit as an MP. Ms Pryce denies the same charge.
Prosecutor Andrew Edis said the truth of Mr Huhne's speeding in 2003 only came out when Ms Pryce sought revenge for Mr Huhne having an affair.
Ms Pryce claimed she was driving and took the points penalty for Mr Huhne, who otherwise would have lost his licence.