Jamie Oliver's programme highlighted the issue

The Lib Dems and the Tories accused the Labour of a gimmicky election stunt.

Quite frankly I don't see how Greenwich ever thought they could do it on 37 pence Ruth Kelly Education secretary Hear the interview

Speaking at the launch of Labour's plans for children, Ms Kelly said she had told her departmental civil servants that she wanted to "do something to raise the standards of school meals" on her first day in office.

She also said she thought it would be very difficult to produce a decent school meal for 37 pence - the amount which the TV chef discovered a school in Greenwich was spending on producing a single school meal.

"Quite frankly I don't see how Greenwich thought they could ever do it on 37 pence," she said.

Schools and local authorities, who set their own budgets and decide what they spend on school meals, would be expected to look at the issue carefully, she added.

"Our commitment today is that a third Labour term will make additional resources available to rebuild and build new kitchens and dining areas."

Parents, teachers and governors are calling for more fresh meat, fruit and vegetables, locally sourced and even organic produce Scolarest, schools caterer Caterer demands cash

From September minimum standards for fat, sugar and salt content in school meals would be enforced, and meals services would be inspected by the Office for Standards in Education.

Ministers are also seeking a voluntary agreement to stop junk food advertising at times when children watch the television.

If that did not work, a third Labour term would legislate to enforce it issuing fixed penalty notices to firms which broke the rules.

The government wants tougher nutritional standards for schools

Shadow education secretary Tim Collins said "genuine solutions" not "pre-election gimmicks" were needed, adding that that a Tory announcement on the issue was coming soon.

"Conservatives would ensure we have more money given to the front-line and allow schools the freedom and resources they need to offer more nutritious meals."

Lib Dem education spokesman Phil Willis said the plans were a "cheap election stunt" to "hide the fact that for eight years under [Tony Blair's] stewardship, our children have been eating the most appalling food".

The Soil Association, which represents organic growers, also said the government had "dragged its feet" and pointed to the stricter regulations already introduced in Scotland.

Plans in the mini-manifesto also include dealing with tobacco sales, tackling internet porn access and more protection from paedophiles.