Broadcasters have warned of "severe consequences" for children's TV if the government slaps a ban on fast food advertising to the under 12s.
This week the cost of such a ban to broadcasters was put at£30m by industry sources.
Media secretary Tessa Jowell warned this week she would be asking industry regulator Ofcom to impose tougher codes on the advertising of junk food to children. A spokeswoman for the Department for Culture, Media & Sport said: "We hope [the advertising code] will be tightened up." Jowell has refused to rule out an outright ban.
The news has alarmed kids broadcasters. Any ban would significantly affect the ad revenues for Nickelodeon, Boomerang, Fox Kids and the Cartoon Network. Other broadcasters with ring-fenced children's strands, such as ITV and Five, would also be affected.
UK advertisers spend approximately£300m each year marketing sugary drinks, fast food, confectionery, cakes and convenience food via TV commercials, according to Nielsen Media Research. Media agency Carat calculates that up to 10% of this spend is concentrated in airtime designated for children.
ITV controller children's and youth Steven Andrew warned that any ban would have "severe repercussions", adding: "Whilst ITV recognises that obesity is a serious public health problem, we do not believe that banning advertising around children's programmes is the solution. It would have severe repercussions for children's programming on commercial TV and would put at risk ITV's major investment in home-grown programmes made for UK children."
Richard Kilgarriff, head of Cartoon Network, shared Andrew's concerns: "The advertising revenue lost through an outright ban is money that won't be invested in programming."
GMTV managing director Paul Corley added: "By banning [snack food] advertising then you risk taking away the funding for children's programmes. You need funding to keep the quality of these programmes high."
Both said that marketers will find a way to get to children whether or not they could use television. "If you force advertisers to take their money out of TV, which is heavily regulated, they'll put it into other ungoverned areas," said Kilgarriff.
Corley said that all the relevant broadcasters were talking to each other about the issue and had had recent discussions about what to do in the event of a ban.
In July the Coca-Cola company said it would not "actively market" any of its drinks products to under 12s.