Retail chain the Co-operative has ordered the publishers of lad's magazines to hide their "lewd" covers or face seeing the magazines removed from shelves.

In the wake of Prime Minister David Cameron's bid last week to restrict access to internet pornography, the Co-op has give titles such as Front, Loaded, Nuts and Zoo until September 9 to deliver the magazines in pre-sealed bags.

The chain, with 4,000 stores across the country, introduced opaque screens on shelves earlier this month to shield children from lewd pictures on covers of the magazines, known for their pictures of scantily clad women.

"As a community-based retailer we have listened to the concerns of our customers and members, many of whom say they object to their children being able to see overt sexual images in our stores," said Steve Murrells, retail chief executive for the Co-operative group.

"Whilst we have tried to mitigate the likelihood of young children seeing the images with a number of measures in-store, the most effective way of doing this is for these magazines to be put in individual, sealed modesty bags," Murrells added.

"The publishers of these magazines now have until September 9 to start providing their own modesty bags, after which any lads' magazine which does not have the relevant bag will not be supplied in our stores."

The Co-operative said the Sport newspaper has already agreed to deliver all editions to stores in bags after the September deadline.

Cameron last week threatened to legislate unless internet giants introduced family filters to let parents block their children from accessing porn by October.

Jo Swinson, Minister for Women and Equalities, said: "Many parents aren't comfortable with the way that sexualised imagery has become like wallpaper -- everywhere from the bus stop to the corner shop.

She added: "Adults should be left to make their own decisions about what legal sexual images they look at, but the place for these is not next to the sweets at children's eye-level. I hope other retailers will follow the Co-operative's lead."