The trial of Vicky Pryce on charges of covering up a driving offence by her disgraced husband Chris Huhne has collapsed after she claimed he made her do it.

In dramatic scenes at Southwark Crown Court, the jury was discharged after failing to reach a verdict on whether economist Pryce, an economist, perverted the course of justice.

Pryce, 60, defended herself against the charge by claiming martial coercion - an obscure defence available only to women.

After four days of deliberation, the jury of eight women and four men was unable to reach a unamious verdict.

Pryce claimed that her ex-husband Huhne had piled pressure on her to tell police that she was driving his BMW when it was clocked speeding in 2003. As a result, he dodged getting three more points on his licence and avoided a driving ban.

Pryce appeared in the dock alone, after former Cabinet secretary Huhne admitted lying about the offence. He may face jail.

Huhne pleaded guilty to perverting the course of justice and then resigned as MP of Eastleigh in Hampshire. He spent two years denying any wrongdoing, after details of the offence became public in 2011.

Huhne, who only narrowly lost to deputy prime minister Nick Clegg in the Lib Dem leadership race, maintained up until the last minute that the claims against him were wild allegations. He even quit as energy secretary in 2012 to fight the charge before his shock about-turn.

During the trial of Pryce, the jury was played a tape of her noisy arguments with Huhne. She collaborated with the Sunday Times' political editor to secretly record exchanges, during which she tried to draw a confession from him.

Pryce admitted on the tapes to wanting to "nail" Huhne for leaving her and the couple's children. He walked out for the marriage to pursue his relationship with PR adviser Carina Trimington.