A charity has called for a ban on junk food television adverts before the 9pm watershed after new research showed parents are being hounded by their children to buy the unhealthy products.

The study by the British Heart Foundation (BHF) found that 70% of parents with children aged four to 16 have been pestered to purchase the products featured in commercials.

A poll of over 2,100 UK parents found that 43% are badgered by their children at least once a week, while almost two in five think junk food TV ads make it more difficult to help their children eat a healthy diet.

Mike Hobday, director of policy at the BHF, wants tighter restrictions on advertising to protect children from making unhealthy choices.

He said: "Regulations for TV and online advertising in the UK are weak.

"Loopholes in the system mean that every day millions of children are exposed to sophisticated marketing techniques specifically designed to lure them into unhealthy eating habits.

"This evidence shows that junk food ads are having a detrimental impact on children's behaviour and are hindering parents' efforts to get their children to eat healthily.

"We cannot allow companies to continue exploiting holes in the system at the expense of our children's health.

"The Government must act now to help give children a stronger chance at fending off future heart disease."