Responding to a growing political storm in the US surrounding screen sex and violence, Walt Disney has decided to enforce stricter rules for the way that R-rated films released under its Touchstone, Hollywood Pictures and Miramax Films labels are marketed, particularly towards children.

Print advertising, trailers and web sites will now include a supplementary explanation for exactly why films like Scary Movie would have been rated R by the Motion Picture Association of America (MPAA), the Hollywood trade body that issues movie certificates.

Disney has also pledged to stop theatre owners from exhibiting preview trailers for R-rated films on screens that then show films released under the family-friendly Walt Disney Pictures label. And any market research for its R-rated films will not be targeted at groups under the age of 17.

In addition, the studio promised to tighten its guidelines for handling ads from other Hollywood distributors on the Disney-owned ABC broadcast network, enforcing a complete network ban on running commercial spots for R-rated movies before 9pm.

Disney's initiatives, which it says are an expansion of an existing voluntary code of practice, come just one day after federal regulators publicly accused the entertainment industry of targeting adult material, specifically violent films, music and video games, to underage audiences. The attack was published in the form of a report by the Federal Trade Commission excoriating the "pervasive and aggressive marketing" of adult material to children.

With just two months to go before the American populace decides on its next president, Democratic hopeful Al Gore and his running mate Joseph Lieberman have also stepped up their criticism of the entertainment industry, despite the fact that Hollywood is has been a heavy contributor to its campaign coffers. And, adding its own voice to the debate, the Federal Communications Commission, announced it would be examining whether broadcasters are promoting inappropriate programming at hours when children are likely to be watching.

At a congressional hearing to be chaired Wednesday by Senator John McCain with Lieberman alongside, MPAA president Jack Valenti is expected to defend Hollywood's marketing practices while conceding that the studios may have occasionally stepped over the line.

In prepared remarks released before his testimony to that Senate Commerce Committee, Valenti called the report "both objective and nonstrident." However, he questioned whether all R-rated films should be subjected to exactly the same treatment since that certificate covers such a wide spectrum of content. "We are not dealing with Euclid's geometry where the equations are pristine and explicit," he declared on Tuesday.