The 12-minute TV ad: Commercials get longer as watchdog relaxes rules

The media regulator yesterday dumped rules preventing extremely long commercials on the main public channels.

It claims that the current limit of seven minutes during off-peak times is unnecessary, as few adverts run this long.

Indiana Jones in Raiders of the Lost Ark - a classic TV movie which could now be packed with even more advert breaks

This means that during the day, or late at night, channels could devote their entire hourly advertising allowance of 12 minutes to a single ad.

The changes, which start in September, apply to public service channels such as ITV, Channel 4 and Five.

They were announced on the same day it emerged that product placement could be allowed on British television.

The controversial practice, common in the U.S., has been approved by the EU. The Government may choose to allow it here - meaning advertisers could pay to have their products used on shows such as The Bill or Coronation Street.

New rules: Ofcom headquarters in London

Consumer groups yesterday warned that the Ofcom guidelines herald a new type of stunt advertising, in which commercials will look like short programmes.

They also say that such long adverts will massively disrupt viewing. Director of the Mediawatch UK pressure group John Beyer said: 'An advert of 12 minutes would be lasting longer than some of the programmes.'

He added that channels would be 'foolish' to run such long adverts, as 'it will actually encourage people to switch off or go to another channel'.

Ofcom has not changed the rules for peak-time viewing, which allow for single adverts of no more than three and a half minutes, as part of the total 12 minutes per hour.

But it has also relaxed the guidelines for advertising during movies on television, allowing more frequent ad breaks.

Mediawatch's John Beyer felt the changes would discourage viewers from watching television

Instead of one break every 45 minutes, channels can introduce them every 30 minutes.

And for the first time audiences will be subject to advertising on religious, current affairs and documentary television shows which last less than 30 minutes.

Ofcom has defended the changes, saying they will help make certain types of programming, such as documentaries, more commercially viable to show.

It said that in terms of advert length, few lasted more than 60 seconds and very few come close to the current seven-minute limit.

It added: 'We remain of the view that restrictions on the length of advertisements on PSB channels are not necessary.

'The high cost of very long advertisements, the practical difficulties of scheduling them and the risk to advertisers that consumers would not engage with them all militate against the likelihood that they would become common.'

It said that even if they did appear at this length from time to time there would be no 'consumer detriment'.

Ofcom is also consulting on proposals which could see an increase in the amount of advertising overall.