The Conservatives have warned that measures set to be unveiled by the government to tackle Britain's obesity epidemic are unlikely to prove effective.

Shadow health secretary Andrew Lansley warned that ministers were set to ignore the recommendations of their own advisers.

His comments came after weekend media reports suggested that John Reid is set to ban television adverts for unhealthy food from being aired before the 9.00pm watershed.

A new food labelling system, possibly using "traffic light" warnings, is also being considered.

But Lansley said the plans, due to be unveiled in tomorrow's public health white paper, would not deliver the expected results.

"The government have been all talk on public health for the last seven years," he said.

"Now they're reaching for a ban on advertising junk food when their own advisers, the Food Standards Agency and Ofcom have said that it is unlikely to be effective."

And he warned that the "traffic light" system would see red warnings given to many staple foods like cheese.

"What the industry is working towards is a system of labelling, showing how foods would represent parts of recommended daily amounts of calories, fats, salts and sugar," said Lansley.

"It would be better now for the government to work with industry towards a single solution, implemented by the industry rather than imposed by government."

Defending the government's approach, the health secretary has said ministers plan to offer support to the public.

"What people want in today's world is as much support and assistance from the government as possible to help them make the healthy choices which them will give them a better quality life and prolong their life," Reid said.

But Liberal Democrat health spokesman Paul Burstow said the white paper was "set to disappoint".

"It will be mixture of half measures that will fail to get to grips with the public health crises this country faces," he predicted.

"Voluntary labelling of fast food will cause confusion and fail to inform the public."