Two more crisp vouchers go into the box

Figures collected by the BBC show that schools have now received equipment worth about �100m as a result of collecting vouchers and tokens.

Clifford Primary school in Herefordshire has just held an "open garden" - one of tens of thousands of school fund-raising events around Britain at this time of year.

The school itself is growing and needs a new classroom.

Under a new government scheme, it will get that only if parents can first raise �60,000 - which is �1,000 per pupil. The government then contributes the rest.

Martyn Jenkins: "Fun - but essential"

The school is so cramped that the head teacher's office is also the staff room, school office and sick room.

Like all schools it now sees fund-raising as essential to its purpose.

"When I first started teaching we used to have events but they were mainly for fun, for social things," said the head, Martyn Jenkins.

"They're still fun but they're for essential things, and if we want to get something in school then we have to think in many ways, 'Well, how can we fund-raise to get it?' "

Like other schools, Clifford also collects the crisp packets and supermarket vouchers which are becoming big providers of school equipment.

How the money adds up

Tesco's has contributed �55m of computers. Sainsbury's vouchers have provided �24m of school equipment. And in its first year, Walkers crisps contributed books worth �15m - a total of �94m from just three schemes.

Add in others, and vouchers have now provided equipment worth �100m.

Aside from collecting tokens, Clifford parents also raise �4,000 a year through fetes and other activities.

Sylvia Morris: "Unfair"

The total raised by all schools in England is now over �230m a year. But some do far better than others.

The Cathedral School of St Saviour and St Mary Overie in the London borough of Southwark raises only �300 a year: some primary schools raise 80 times that much.

The head teacher, Sylvia Morris, says there is also a struggle to collect vouchers.

"It does seem grossly unfair that that actually depends on how many children you have in your school, and how many of those children happen to shop in those particular shops or buy those particular products," she said.

Anne Mountfield: "What is it we want?"

Experts say teachers now feel obliged to spend time raising funds for basics, not extras.

Anne Mountfield of the Directory of Social Change, which recently published a report on the subject, said: "It is time everybody decided whether we wanteschools to be funded as a public service from public expenditure or whether we are now expecting schools to raise part of their income from fund-raising, charitable trusts and companies."

Fund raising may be a tiny part of school's total budgets but it is increasingly vital and, inevitably, unequal.