Teenage girls should be taught at school about the benefits of sexual abstinence, an MP has said.

Tory Nadine Dorries told the Commons that while secondary school pupils were shown how to put condoms on bananas and to self-diagnose sexually transmitted diseases (STDs), they should also be told "how to say no".

"We need to let young girls know that to say no to sex when you are under pressure is a cool thing to do," she said.

Unveiling her ten minute rule bill on 4 May 2011, Ms Dorries called for schools to give girls aged 13 to 16 extra sex education, including the benefits of abstinence.

"This is about giving empowerment to young girls," she explained.

Ms Dorries went on: "The answer to ending our constant struggle with the incredibly high rate of teenage sexual activity and underage pregnancies lies in teaching our girls and boys about the option of abstinence, the ability to 'just say no' as part of their compulsory sex education."

But Labour's Chris Bryant described Ms Dorries' bill as "the daftest piece of legislation" he had seen, saying there was no evidence teaching abstinence would lead to fewer pregnancies or STDs.

"The single most important thing we can do for any young person is give them the self-confidence to be able to make good decisions for themselves," he added.

MPs voted 67 to 61, a majority of six, in favour of allowing Ms Dorries to bring forward her bill. It will receive its second reading debate in January.

Ten minute rule bills do not stand much chance of becoming law unless they are adopted by the government.