This sounds like a product you would see on late night infomercial TV. “Billy Mays here for the anti-stab knife. . . are you sick of your son or daughter threatening you with your own kitchen knives? The nerve of them. . .Are you tired of people breaking into your house to have them use your own knives to rob you? Then this is the product for you”. Of course there would be the disclaimer: “WARNING: Does not prevent you from getting your throat sliced”.

First ‘anti-stab’ knife to go on sale in Britain

The first “anti-stab” knife is to go on sale in Britain, designed to work as normal in the kitchen but to be ineffective as a weapon.

The knife has a rounded edge instead of a point and will snag on clothing and skin to make it more difficult to stab someone.

It was invented by industrial designer John Cornock, who was inspired by a documentary in which doctors advocated banning traditional knives.

Mr Cornock, 42, from Swindon, said that the knife will cut vegetables, but will make it almost impossible to stab someone to death and will reduce the risk of accidental injuries.

He said: “It can never be a totally safe knife, but the idea is you can’t inflict a fatal wound. Nobody could just grab one out of the kitchen drawer and kill someone.”

The knife is expected to sell for around £40-50 and has been tested with “very favourable” results by the Home Office’s Design and Technology Alliance – set up to research products that can deter crime.