The daughter of ex-cabinet minister Chris Huhne has revealed how she fought off a cab driver who tried to sexually assault her.

Lydia Huhne, 24, managed to headbutt the man after he locked the doors of the car, climbed into the back and touched her face and breast.

A bouncer had hailed the cab for her in the early hours of Sunday as she tried to return home from a friend's birthday party in Clapham, south London.

Today Miss Huhne, who co-runs a theatre company, called for all children to be taught self-defence.

She said: "I really do think it's important that self-defence is taught in schools. If it wasn't for me having done fight scenes in plays I wouldn't have ever thought about headbutting.

"Luckily nothing really happened because I reacted fast. If another person had got in the car and hadn't had training it could have resulted in something much more dire."

The performer, who works for Burnt Out Theatre, said she wanted to turn the experience into something more positive, particularly after negative publicity surrounding her parents - former energy secretary Huhne and his ex-wife Vicky Pryce.

They were both jailed for eight months for perverting the course of justice after Pryce revealed that she had taken speeding points on the disgraced MP's behalf.

Miss Huhne said: "There has been so much publicity around my family and it's been negative, so I wanted to use this horrible experience to raise awareness and turn it into something positive."

She also warned against taking unlicensed cabs.

"That's the first time I had ever used a non-licensed cab," she said. "However close you are to home, however safe you feel, you must never get in those cars. They are just touters.

"I feel quite lucky that nothing really serious happened, I'm pretty shaken up by the whole event."

The driver was a stocky Afro-Caribbean man.

Scotland Yard said it is investigating an allegation of sexual assault by touching in Lambeth borough.

A spokesman said: "The allegation relates to an incident in Lambeth in the early hours of Sunday, February 9.

"The incident is being invested by the sexual offences team based within the MPS Safer Transport Command.

"Anyone with information that may assist the investigation should call police on 101 or, to remain anonymous, call Crimestoppers."