A catering firm has threatened not to bid for school dinner contracts in England unless funding increases.
Fears over the health effects of school meals have grown
Scolarest, which supplies 1,400 state schools, wants 55p a day per child for food, compared with the average of 45p nationally for primaries.
But to provide healthy, freshly cooked meals, up to 70p would be a more realistic figure, the company added.
Its announcement follows a government promise of more money to improve nutrition standards in English schools.
TV chef Jamie Oliver is running a campaign for extra cash for school meals, but his demand is for 50p - less than that of Scolarest, which is part of the Compass group.
A company spokeswoman said: "The demands of the school meals service have changed significantly over the last two years.
"Parents, teachers and governors are calling for more fresh meat, fruit and vegetables, locally sourced and even organic produce, more home-cooked options and a whole change in culture and expectations of the service.
"No caterer, whether a contractor or an in-house operation, can continue to meet these demands on specifications and budgets set three to five years ago."
The decision not to bid for lower-funded contracts was not a reaction to Mr Oliver's campaign, the spokeswoman said.
It had been taken "independently, towards the end of last year".
The average spending on meals in Greenwich - the London borough featured in the Channel 4 show Jamie's Dinners - was 37p a day per pupil.
The Education Secretary, Ruth Kelly, has promised to make "additional resources available to rebuild and build new kitchens and dining areas".
"Quite frankly I don't see how Greenwich thought they could ever do it on 37 pence," she said.
The Local Authority Caterers Association has already asked for more government money to raise school meals standards.
About a dozen education authorities offer no meals service at all.
So many primary schools, in particular, have no kitchens.
A Labour Party spokesman said that, if they were bidding for capital funding to improve their premises, "building the capacity to cook fresh hot meals on the premises" would be viewed as a priority.