Cabinet heavyweights John Prescott and Charles Clarke are to serve on a new top-level group stepping up the Government's war on obesity.
Ministers' failure to curb Britain's bulging waistline will be subjected to fierce criticism this week in a Commons committee report on the issue.
In a report to be published on Thursday, the health select committee will say that weight-related health problems are costing the nation almost £5bn a year.
But Whitehall turf wars have repeatedly delayed simple measures to tackle the problem such as a ban on advertising junk food on children's TV and better labelling on food, the MPs will claim.
Officials moved to blunt the attack this weekend by revealing that a cross-government body has been set up to tackle the issue.
John Reid, the Secretary of State for Health, is to chair the new cabinet committee on public health that is expected to meet for the first time this week. Members include Tessa Jowell, the Secretary of State for Culture, Media and Sport.
The body will have to thrash out a number of highly contentious issues before the Government unveils in July its proposed legislation to improve the nation's health.
Mr Reid is also expected to set a formal target of halting the increase in obesity, The Independent on Sunday has learnt. Although he has repeatedly insisted he favours policies that help people to choose healthier lifestyles, officials signalled that he is hardening his attitude on the measures needed to tackle childhood obesity.
Melanie Johnson, the Public Health minister, hinted last week at an outright ban on junk-food adverts on children's TV. She has previously expressed disappointment that the food industry has not done more voluntarily to reduce levels of fat and salt in food.
Until now Ms Jowell, who is responsible for advertising, has resisted calls for a ban, pressing instead for a voluntary code overseen by Ofcom, the media regulator. The final decision on what the Government can do to lure children away from high-fat and salty food will be taken after a Food Standards Agency (FSA) consultation concludes next month.
The options it put forward include the use of cartoon characters and celebrities only to promote healthy options.
The body found that 92 per cent of children derive too much of their energy from saturated fat and that four- to six-year-olds eat up to 50 per cent more salt than is good for them.
Around 40 per cent of adverts on children's TV are for food, the FSA found, with most promoting confectionery, fast food, sugared cereals, savoury snacks and soft drinks.