Private schools have been told to open up their swimming pools to local primaries as part of a new Government plan to boost swimming lessons.

It comes amid concern about levels of child obesity, with more than 22,000 dangerously obese children leaving primary school this year.

Almost half of pupils are unable to swim the required 25 metres by the time they leave primary school, even though swimming lessons are a compulsory part of the national curriculum.

The Education Secretary, in partnership with the Independent Schools Council (ISC), is urging private schools to help children from neighbouring state primaries learn to swim by allowing them to use their sports facilities.

Headteachers should also encourage a “culture of healthy competition”, Damian Hinds said, after a Government survey from earlier this year showed that almost half of all state primaries offer no competitive sports events such as a school sports day.

72 per cent of primary schools use public facilities for their swimming, while a quarter use their own pool or another school’s pool.

Just over half of private schools already share their facilities with other schools, as well as some offering coaches to local primary schools.