THE Government's performance-related pay scheme for teachers has been condemned as potentially "unworkable".
Recruitment expert Professor Alan Smithers said this week that the scheme was too complex and could put off prospective teachers.
He added that, in order to attract the staff the profession needed, the Government would have to pay teachers an extra pound;18 billion a year - equivalent to seven pence in the pound on the basic rate of income tax.
The claims from Professor Smithers, head of Liverpool University's centre for education research, echoed a separate warning from heads' leaders that performance pay alone would not avert a dire shortfall in teacher supply.
Meanwhile, the Conservatives condemned the key plank of the Government's pay proposals - pound;2,000 bonus payments for good teachers with experience - as a "sham". The Tories were responding to reports that nine out of 10 applicants will get the bonus.
Based on the pilot of the scheme, heads' leaders expect the success rate to be at least 90 per cent.
But, in his research published this week, Prof Smithers said similar performance pay schemes introduced around the world had either failed or had had to be radically changed.
The Government introduced three major reforms as well as the pound;2,000 "threshold" payments: performance management, fast-track promotion and the new advanced skills teacher grade.
But the four schemes relied on quite different assessment criteria, suggesting the Govenment had no clear concept of what constituted a good teacher.
The complexity of the threshold system also laid it open to legal challenges from teachers missing out on payments.
"We suspect that the Blair government's proposals will prove unworkable if only because of their complexity - which betrays a lack of understanding of what good teaching involves," said Professor Smithers and his colleague Dr Pamela Robinson.
Even with the pound;2,000 bonuses for experienced teachers, nearly half in the state sector would be earning under pound;26,000 a year, a figure unlikely to persuade graduates to shun other professions or private schools.
Meanwhile, in a letter to the School Teachers' Review Body, the National Association of Headteachers this week said it would be a serious mistake for the Government to rely on the new pay structure to boost recruitment and retention.
The claim comes amid fears that schools all over the country will start the new year with massive staff shortages that will force them to continue relying on unqualified and supply teachers.
Research by the Secondary Heads Association showed that, in London suburbs, only 56 per cent of teaching vacancies were being filled, while 50 per cent of heads surveyed wanted to leave the profession. John Dunford, the association's general secretary, said that only a significant improvement in pay and conditions would ease the situation.
A Government spokeswoman denied the threshold scheme was overly complex, adding that performance pay was an accepted part of working life in many other professions Leader, 8