Ed Balls has told state school heads to do everything to cut costs for parents during the credit crunch.
New research has found that sending a child to state secondary school costs parents almost Pounds 1,200 a year on average and Pounds 683 is spent on supporting primary-aged children at school.
The costs come from paying for uniform, school trips, extra materials, charity donations and school fundraising. The research by BMRB, for the Department for Children, Schools and Families, found that overall costs had increased since 2003 in real terms by an average of Pounds 34.
The research, carried out in 2007, found 16 per cent of parents were not happy with the cost. Six per cent said it was very difficult to meet the costs.
It also found that compulsory charges were imposed for one in 10 curricular trips in primary schools and three in ten curricular trips in secondary schools, even though no compulsory charge should be made for these trips. A day trip cost Pounds 9.47 on average in primary schools and Pounds 21.70 in secondary schools. Half of the 1,500 parents polled said that they sometimes felt pressured into paying for school trips.
Ministers said it was unacceptable and unlawful for any school to ask for compulsory contributions towards school trips that were part of the normal curriculum - as some schools admitted they do.
Mick Brookes, general secretary of the NAHT, said that the situation was not as clear cut as it appeared: "It can't be a compulsory contribution; it has to be a voluntary one. But on the back of that, if parents are not prepared to make a contribution the trips will be cancelled.
"For parents who are in dire financial straits most schools will operate a system, very quietly, which helps children to go on school trips perhaps with a school fund or knocking off some of the costs. But school trips can add up to thousands of pounds and there needs to be a dose of reality behind what the government is saying."
One in six parents said they had to buy all items of uniform and PE kit from a designated sole supplier or their school itself - although there is non-statutory guidance advising against this.