British lads' mag Nuts saw its circulation collapse by more than a quarter in the first six months of 2013, as supermarkets came under pressure from feminist campaigners to cover up their displays featuring glossy men's magazines.

Figures from the Audit Bureau of Circulations show that in the half year to June Nuts had a circulation of 58,781, 26.7% fewer than in the previous six months.

Nuts, which is owned by publishing group IPC Inspire and was launched in 2004, was asked by the Co-operative supermarket to put its magazines in modesty bags to cover up the front pages, which feature scantily-clad women in lingerie.

However it refused to do so and will no longer be stocked at Co-op stores. Rival lads' mag Zoo has also refused to use modesty covers.

All similar glossy lads' mags have until 9 September to start using modesty bags or the Co-op says it will no longer sell them.

IPC Inspire hit back at the Co-op over its decision to ban lads' mags that refuse to use the bags.

"The Co-operative's knee-jerk attempt to restrict access to a product that consumers have enjoyed for nearly a decade is wrong," said Paul Williams, managing director of IPC Inspire.

"Nuts takes its obligation to craft products that are right for consumers and retailers alike very seriously, and for a number of weeks now we have had new covers in place, which have a more conservative tone.

"As has been widely reported in the media in recent weeks, this is no longer a question of whether or not you like men's magazines, it is a question of how far you can restrict the public's ability to consume free and legal media before it becomes censorship."

Lose the Lads' Mags

Retailers have been given an ultimatum by women's rights campaign group UK Feminista.

As part of its "Lose the Lads' Mags" campaign, UK Feminista told supermarkets they face a legal challenge under the Equality Act 2010 unless they stop stocking magazines which feature half-naked women on the front cover.

"Lads' magazines have had an easy ride for years and they've realised they're potentially coming up against legislation," Kat Banyard, director of UK Feminista, told IBTimes UK in May.

"People haven't known their legal rights. The point of the campaign is to make people aware of their rights and empowering them take action. Retailers now know they will be held to account."