Jane Davidson, education and lifelong learning minister, said the Food in Schools working group had already eaten dinners in schools across 12 local authorities and so far their verdict was “excellent.”

The group’s final findings will be made known to opposition Assembly members as part of cross-party negotiations in April 2006.

Ms Davidson gave an update to Assembly members on her plans to improve nutrition in schools and encourage children to opt for more healthy options. However, Conservative education minister William Graham said much more money needed to be spent on school dinners to raise standards.

He told the chamber: “The amount of money spent on school dinners ranges from 40p in Cardiff to 69p in Powys - modest amounts to say the least.”

The party has already accused the minister of being “too late” in delivering on healthy eating plans. It claims more has been done in England where celebrity chef Jamie Oliver campaigned to improve the quality of food going into schools.

Plaid AM for south Wales central, Leanne Wood, said the E.coli outbreak had dented parents’ confidence in school dinners.

Labour’s Jeff Cuthbert, AM for Caerphilly, said more should be done to educate children on the nutritional content of food.

He told fellow AMs: “Studies show children don’t know what a chip is made of. Some think it is made up of eggs, others flour, and one even thought an apple.”

Meanwhile, David Melding, AM for south Wales central, said cookery lessons should have more importance in the national curriculum.

Peter Black, Liberal Democrat chairman of the Assembly’s education and lifelong learning committee, said that not enough parents, or pupils, understood what healthy eating was.

Ms Davidson acknowledged the E.coli outbreak had made parents and pupils lose faith in the system, but said the infection was a hygiene matter and not about the nutritional content of food. At present the Welsh Assembly does not have the power to ban junk food such as chips, fizzy drinks and sweets from schools. She highlighted schemes in Carmarthenshire as a “beacon of excellence” for others to follow.

A white paper from the Department for Education and Skills, called Higher Standards, Better Schools for All, includes proposals to make nutritional standards apply to food and drink in school settings, with Wales included.

Ms Davidson said this could provide money to give free fruit to children three times a day, and give local authorities freedom to try new approaches to school meals and refreshments.

Plans to attack the junk-food culture among Welsh schoolchildren include setting a minimum nutrition guide for schools; fruit tuck shops; the piloting of healthy vending machines; and the placing of water coolers in every school.

Ms Davidson said: “A balanced diet is important both to school performance and health. I welcome this update which demonstrates our commitment to improving the health of children.”