Plus size clothes are on sale on Britain's high streets for children as young as three, in what health campaigners say is a sign that childhood obesity has moved beyond epidemic proportions.

The comments come as it has emerged that high street retailer Next is selling a range of "plus fit" clothing for children aged between 3 and 16.

Included in the range, which is for boys and girls, are a number of pairs of jeans and tracksuit bottoms designed for children with larger than average waists.

The retailer's "age 3 plus fit" trousers have a waistband which is 5cm larger than a standard "age 3" waistband, at 58 cm compared to 53 cm. "Age 10 plus fit" trousers have a waistband of 69 cm in size, compared to a 64 cm measure on standard "age 10" trousers.