Youngsters who failed to wear the helmets would be fined at a similar level to adults receiving parking fines. The punishment could see them - or their parents - paying up to £40 when they broke the law.

The protective headgear for young cyclists bill is one of seven private member's bills announced yesterday, which could just become law if parliamentary time allows.

Other bills include one to prohibit large stores trading on Christmas Day; to license gangmasters, who provide workers for temporary jobs; and to screen for conditions that can lead to sudden cardiac death in the young.

The bill forcing youngsters to wear cycling helmets was launched by Eric Martlew, the MP for Carlisle, after he was lobbied by the Bicycle Helmet Initiative Trust, a charity run by a nursing sister with extensive experience of children's head injuries caused by crashes while cycling.

Around 50 children a year die from head injuries caused by cycle crashes.

Mr Martlew, 55, said that he had been inspired to adopt the bill in part because he experienced similar injuries. At the age of five, he was hit by a petrol tanker. "I suffered head injuries, so I personally remember the trauma and pain of operations and the separation from my parents," he said.

He said the bill was not dissimilar from legislation which demands children under the age of 14 wear helmets when horseriding, and denied that it was unnecessarily prohibitive.

"People talk about the nanny state, but nannies look after children, and that's what this bill seeks to do," he said. Such arguments did not matter "if you save 20 or 30 children each year".

He also denied that the fine system was too draconian. "Fines would be very similar to parking fines. But what we are not about is criminalising children."

The bill - seventh in the list of private member's bills to be heard - will have a second reading on April 23.