Doug McAvoy, the General Secretary of the National Union of Teachers, has called on other teachers' unions to hold a joint ballot on the government's proposals to award larger pay rises to more successful teachers.

The NUT wants to organise a collective opposition to the government's restructuring of teachers' pay, with a ballot providing a springboard for further action.

The government wants to introduce performance-related pay this year

"This is a unique opportunity to unite the profession against the reintroduction of the discredited payment by result system," said Mr McAvoy.

"Our own members are totally opposed to payment by results and I am sure other teachers will share that view. An indicative ballot will demonstrate the strength of feelings of the profession beyond question.

"It will deter the government from imposing changes to the appraisal procedures this year. It will cause the government to think again."

The NUT's campaign against the linking of pay to performance comes as a headteachers' union has called for a slowing down of the pace of reform.

The NAHT says that the government's plan to introduce an appraisal and performance-related pay in September 1999 is "unrealistic" and has called for the changes to be postponed until September 2000.

Under the pay reforms proposed in the government's Green Paper, successful teachers and schools would receive achievement-related payments, with an appraisal system determining whether teachers merit an extra increase in salary.