Are playground games dying out?

Len Almond, from the British Heart Foundation, said some primary schools used the literacy and numeracy hours as an excuse to cut PE lessons.

And he said playground benches were also to blame for children becoming less active.

Mr Almond said there could be a link between rising childhood obesity and cuts in PE at school in England.

Mr Almond, who is also the director of the National Centre for Physical Activity and Health, was speaking to the health select committee, which is carrying out an inquiry into obesity.

Asked about the effect of national programmes such as the literacy and numeracy hours, he said: "There has been a major reduction in the total amount of physical education time."

The literacy and numeracy hours were an excuse some schools used.

"Physical activity is a very low priority of head teachers and senior staff."

He said skipping and other playground games were dying out in schools.

Dual focus

Earlier this year, the government said it wanted schools to offer a wider variety of sports.

It said it was working to promote enjoyment and excellence in the curriculum.

Primary schools are also being given more freedom to move away from sharply defined literacy and numeracy hours.

A spokesperson for the Department for Education and Skills said: "The most successful primary schools combine both a focus on numeracy and literacy with sport and creativity.

"It is not one or the other because sport helps children to do better in maths and English.

"That's why our primary strategy, building on progress since 1997, enables schools to do both."