A TES Cymru survey has revealed that headteachers at schools affected by the E.coli outbreak believe the quality of school dinners "is as bad as ever".
The damning verdict on meals served in school canteens comes as four new cases of E.coli in primary-school pupils are confirmed. The same strain identified in the latest victims has already killed five-year-old Mason Jones, whose funeral was held on Monday, and made 163 people, mostly primary pupils, seriously ill.
However, most heads willing to talk anonymously about the impact of the infection say children are still at risk.
As TES Cymru went to press, Abercynon infants school in Rhondda Cynon Taf remained closed in a bid to contain the spread of new cases. The 64-pupil school escaped the first outbreak that swept through schools in September.
Public health officials have confirmed the latest cases are not the result of eating school dinners, and were passed on from infected people. But some heads have described school dinners as "bloody awful" and "appalling".
School meal uptake in some of the affected schools has dropped by half.
Out of 23 heads asked about the quality of the dinners, 10 said they had serious concerns, seven refused to answer and six said they were relatively happy.
One head had written to the local authority demanding changes before the E.coli outbreak, but has still not had a reply. In another school, a head said: "The food is very cheap. There are fish shapes which contain no fish, and beefburgers made of reconstituted chicken."
Another said his staff went to the chip shop, or brought in food.
Irwyn Wilcox, head at Ysgol Yr Eos in Penygraig, claimed only "parent power" could bring about change. He said: "I believe food should be sourced locally and cooked on the premises."
But there was praise for the "first-class" handling of the outbreak by local authorities and all 23 heads agreed officials had been right not to close schools.
Most of the complaints come from schools in Rhondda Cynon Taf (RCT), where new initiatives announced last year were supposed to ensure meat was sourced locally, and of good quality. The authority has since abandoned its local Lamb for Lunch scheme pending the public inquiry into the outbreak.
A spokesperson for RCT said: "Our contracts require that all food provided is in accordance with the highest standards for preparation."
The survey results come as Jane Davidson, education and lifelong learning minister, prepares to give a statement to Assembly members on her plans for food and nutrition in schools.
Opposition AMs have branded her plans as "too little, too late". In England, Tony Blair announced radical plans eight months ago on the back of a campaign by celebrity chef Jamie Oliver.
Janet Ryder, Plaid Cymru's shadow education spokesperson, said: "Not enough is spent on school dinners in Wales. The E.coli outbreak begs for action to be taken to raise standards."
But an Assembly spokesperson said: "We are determined to help improve the health of children and young people in Wales with a whole-school approach to food and nutrition. We lead the way in the UK with this approach."
The first meeting of a cross-party committee to draw up terms of reference for a public inquiry into the E.coli outbreak was held on Monday. Professor Hugh Pennington looks likely to oversee it. He headed an inquiry into the UK's biggest outbreak in Scotland in 1996 which killed 17 people.