The Labour party was this week promoting its pledge to improve nutritional standards for school lunches.
But its announcements were overshadowed by comments by Cherie Blair, who criticised the meals at her four-year-old son Leo's school.
"They are not terrific to be honest," the Prime Minister's wife said during a visit to a Birmingham school. "I am seriously thinking about sending him in with a packed lunch."
Teachers taking part in a weekly online poll for The TES said that they were also disgusted with the quality of school dinners.
School staff are being invited to fill in an "e-jury" questionnaire each week to give their verdicts on different issues as the election campaign unfolds.
Nearly half of the teachers who took part this week said they either never touched school meals or ate them less than once a month. Of the 257 teachers who participated, 60 per cent rated meals at their school as only tolerable. A further 14 per cent described them as inedible.
A lucky 2 per cent said their school dinners were gourmet while 22 per cent said they were rather good. Only a sixth said they ate them every day.
The vast majority of the school staff said they believed there was either definitely or probably a link between junk food and pupil behaviour.
"I am sick of teaching nutters in the afternoon," one teacher wrote.
"They're either completely barking after all the e-numbers or dead to the world from the stodge."
This week, the Liberal Democrats topped the e-jury poll with 33 per cent support. Labour had 21 per cent, the Conservatives 10 per cent, the Green party 4 per cent and the UK Independence party 1 per cent.
The most popular education policies were those which would improve pupil behaviour, followed by those that would reduce class sizes and the introduction of Reading Recovery programmes.
Primary Forum 24 Teachers can take part in next week's e-jury and enter a prize draw to win up to pound;100 in Amazon vouchers: see www.tes.co.ukelection2005ejury