Schools could see a 23 per cent increase in funding if they were allowed to reclaim tax on items purchased, said the Irish National Teachers Organisation (INTO) on the closing day of its conference.

Louise Walsh, a teacher at Curragh girls national school, said business was allowed to reclaim VAT but schools were prohibited from doing so. They were being, in effect, double taxed. The INTO will now campaign for schools to be exempt from VAT.

Delegates heard how primary schools across the country were struggling to pay for basic services such as light and heat, meaning that investment in computers and technology often has to come a distant third.

Delegate Adrienne Nolan said children were being asked to sit beside radiators or keep their coats on until lunchtime. Some schools were simply hovels.

Brendan Horan, a member of the central executive committee (CEC), said he first spoke on inadequate funding of primary education 10 years ago but nothing had changed. "We need parity of funding with secondary schools; the basic utility costs are the same. But the silence from management and parent bodies is deafening."

Kathryn Crowley, a teacher from Dublin, told how school principals were having sleepless nights because of the pressures of fundraising. "We're tired of baking Rice Krispy buns and selling them to each other."

Teachers also heard how Deis (disadvantaged) schools struggled to retain staff. Anita Hogan, a delegate from INTO's Dublin North West branch, said children living in poverty had been sacrificed at the first sign of an economic downturn. "The saddest part of the cuts is that the areas targeted were beginning to work: children from Deis schools showed improvement in standardised tests, participation in third-level was increasing, and children from marginalised Traveller communities were beginning to see education as a realistic pathway to a better future. Then we decided to divert resources and the good work started to unravel."

Pat Crowe, a member of the union's CEC, said young teachers in Deis schools only stayed a few years because of challenges in dealing with difficult behaviour, with many going on extended sick leave.

Mary O'Mahony is a resource teacher from an all-boys disadvantaged school in Tuam, Co Galway, with a student profile that consists of 26 per cent Traveller children, 30 per cent non-Irish nationals and 20 per cent from disadvantaged backgrounds. She told how, since the recession, her school has lost two English-as-an-additional-language teachers and the visiting teacher for Travellers. "Traveller children and children from foreign national backgrounds have significant educational needs, and the school is working hard but struggling to meet them," she said. "Many other children with lower standardised test scores are losing out."

Michael Whelan of the CEC said there was a high concentration of small schools with the children of unemployed and low-waged families in counties including Clare, Kerry, Cork and Mayo. There should be a grant for children from disadvantaged backgrounds attending non-Deis schools, particularly in areas of rural disadvantage.