"Share bags" of sweets and chocolates should be banned because children simply eat them all in one go, campaigners have said.

Action on Sugar has called for a total ban on price promotions on confectionery after it found retailers offering bumper "sharing packs" at better value than smaller "individual" sizes.

More than one in five adults (22 per cent) eat the sharing bags alone, in one go, with the figure rising to 35 per cent among 16 to 24-year-olds, its survey found.

Some chocolate confectionery sharing bags contain 29 teaspoons of sugar - four times an adult's maximum daily sugar intake.

Confectionery consumption is the second highest contributor to sugar intake in children after soft drinks.

Action on Sugar claimed the removal of price promotions on high sugar products could cut almost two teaspoons, or 7g of sugar, on average from every individual's diet per day.

At the time of its survey in December and this month, the organisation found Tesco, Asda, Sainsbury's, Morrisons, Co-op and Waitrose were all offering price promotions on some sharing bags, selling them for as little as £1 and making them comparatively better value for money than smaller pack sizes.

The campaign group is calling on the Government to "immediately revise and strengthen" its childhood obesity plan.