Some schools in Bradford have huge six-figure deficits while others are sitting on massive surpluses, new figures reveal today.

Startling disparities are revealed between schools which have run into the red by up to £843,000, and others with as much as £952,000 in the bank.

But head teachers have defended their bank balances blaming them on a host of complicated reasons, including money being carried over for building work and computer replacements, and overspends due to unexpected falls in pupil numbers.

The full list of schools' deficits and surpluses at the end of the last financial year shows some schools had huge surpluses, even though Bradford spends less on education than similar local authorities.

In total, 137 primary schools and 16 secondary schools had £14,798,839 in reserve.

But the remaining 21 primary schools and 12 secondary schools were a total of £5,389,498 in debt.

The issue has come under the spotlight during an inquiry into school funding at Bradford City Hall.

Education chiefs have criticised large surpluses, saying there are no good educational reasons and that in a few cases, mismanagement might be the cause.

From April 2005, schools in Bradford which hold more than the recommended amount in reserve face having the excess cash 'clawed back' by Education Bradford and handed out to other schools.

The Schools Forum, made up of head teachers, has agreed the new Government policy should be implemented in the district.

Presently schools have to explain themselves to Education Bradford if they are overspent or have large amounts of surplus cash, but there are no sanctions against them.

Guidance from the Department for Education and Skills is that primary schools should carry forward a surplus of no more than eight per cent of their budget, and secondary schools five per cent.

Councillor David Ward, executive member for education on Bradford Council, said: "Clearly we are putting more money into schools but we need a more sophisticated way of targeting it. Some schools have special problems often beyond their control and we need to find ways of helping them"

Hanson School head teacher Tony Thorne, who is chairman of Education Bradford's Finance Strategy Group, said schools had a duty to their pupils to spend the money they were given in any particular year - not hoard it.

"I think it's absolutely criminal," said Mr Thorne, whose school with 1,900 pupils is the largest in the district. "The money you get in a particular year is revenue, and should be spent on things like more books or teachers, or on remodelling the workforce."

Richard Kunicki, head teacher at Barkerend Primary, which in official figures has a surplus of £384,817, said people running primary schools were cautious with funds because they did not trust the education authority.

"I am not embarrassed by this carry over figure, we have plans for it," he said. "Frankly we don't trust the figures we're given until we actually see the money. You build up a contingency because you have been let down so many times before."

John Howarth, of the Bradford branch of the National Union of Teachers, said: "Schools have been erring on the side of caution since the re-organisation. If you can put reassurance back into schools they will not feel they need these surpluses. Trust has to be restored."

Beverley Ledra, head teacher at Heaton Primary, which has a surplus of £429,763, said the cash was earmarked for building work that had overrun.