The award is part of a state-wide performance scheme. However, the proposal proved more successful than the state could afford, with more teachers than expected reaching the targets. The payments, for some staff, have now had to be halved.

More than 3,750 teachers will be paid bonuses of $10,000 (pound;6,970) and a further 7,500 teachers will be paid $5,000 (pound;3,485). District officials and teacher unions choose which teachers from the best-performing schools are awarded the bonuses. These payments have been delayed by a legal challenge. But the across-the-board cash incentives for teachers will be 25 per cent smaller than promised because so many schools - 67 per cent - have qualified.

Under a programme to encourage school reform, teachers in any school that raises standardised test scores by 5 per cent were to be paid $800 (pound;557) each, but because 4,502 schools qualified they will get the smaller amount, and with tax dedctions will receive only half of what they were led to expect.

The fiasco has put teachers in the undignified position of demanding cash from state officials who, for their part, say they simply underestimated how much money would be needed.

The incentive programme was announced in 1999 to give a boost to school reform. Teachers and administrators at the lowest-performing schools were also to be paid an additional reward if their students’ scores improved.

The $25,000 bonus programme was challenged in court by teachers at Jedediah Elementary School, Sacramento, after legislators changed the rules to require that the bonus-earning improvements in schools’ performance be measured over two years instead of one.

Jedediah Elementary showed a huge gain in test scores last year, but because the school had posted a slight drop the year before, they were disqualified from the bonus programme. A judge has ruled against them, but the lawsuit has held up the distribution of bonuses to educators state-wide while an appeal is being considered.