A new website is to allow parents to blow the whistle on inappropriate sexual imagery in TV shows, adverts or products.

The Parentport site – www.parentport.org.uk - gives parents the opportunity to lodge complaints that will be followed up by an Ofcom investigation.

The site is being launched by David Cameron as part of his drive to end the sexualisation of children in Britain.

It was one of several recommendations to come out of a government review led by Mothers’ Union chief executive, Reg Bailey, which concluded that today’s children are being surrounded by a “wallpaper” of sexual imagery that is robbing them of their childhood.

Other measures being introduced by Mr Cameron include a ban on sexually explicit advertising near schools and under-15s being “brand ambassadors” for certain products.

The launch of the website coincides with the announcement that leading web providers BT, Sky, Talk Talk and Virgin are to give parents the option of blocking access to explicit websites.

Protection will be available not only for PCs, but also for smart phones and laptops.

The Bailey Review uncovered widespread discontent among parents over the prevalence of sexual imagery in society.

Last month Ofcom warned TV broadcasters to be more careful about the programmes and music videos that they show before the 9pm watershed in order to protect children.

The announcement followed the public outcry over last year's X Factor final which featured sexually suggestive performances by American pop stars Rihanna and Christina Aguilera before the watershed.

Ofcom received over 4,000 complaints about the show, although its investigation concluded that the content was still "at the very margin of acceptability".