Thousands of teachers' salaries will be cut under a new pay deal agreed between the Government, employers and five of the seven teaching unions.
Management allowances worth up to pound;10,836 will be scrapped and levels 4 and 5 of the upper pay scale will be replaced with an "excellent teachers" scheme available only in schools which say they can afford it.
Mary Bousted, general secretary of the Association of Teachers and Lecturers, said: "It has been a difficult agreement to reach and no one is saying teachers will be jumping up and down about it."
The new system aims to ensure payments are made only for specific responsibilities for teaching and learning and not used to retain staff, reward general good performance or pay for administration. It comes as a School Teachers' Review Body survey reveals that hours worked by primary heads and teachers have increased since the implementation of the workforce deal that was designed to cut workload.
Classroom unions that signed up to the 2003 deal blame primary heads and governors, and are threatening industrial and legal action if the situation does not improve.
As revealed in last week's TES Cymru, the signatories of the workload agreement have proposed replacing the five-tier management allowance system with new "teaching and learning responsibility" (TLR) payments.
The current management allowances are worth between pound;1,680 and Pounds 10,836 a year. If the TLR proposals are accepted by the pay review body, the head of a large to medium-sized department would get pound;6,500-Pounds 11,000, while those with lesser responsibilities would receive Pounds 2,250-pound;5,500.
All schools will have to carry out staffing reviews by the end of next year to decide who qualifies for the payments. Teachers receiving allowances for admin tasks, recruitment and retention reasons, or as rewards for good performance, are unlikely to qualify.
Three years after the review, their existing allowances will be wiped out.
The National Association of Head Teachers predicts that several thousand teachers will be affected. More than half of all teachers receive the allowances and the new system is expected to cost less.
Steve Sinnott, general secretary of the National Union of Teachers, excluded from the joint pay talks, said the plan was a recipe for "turmoil and uncertainty".
Heledd Hayes, NUT Cymru's education officer, said the proposals would demoralise Wales's ageing teachers. Those close to retirement might find their final salaries reduced by the loss of existing management allowances - with consequent reductions in their pension entitlement.
"We will be looking at it very closely. This is not designed to improve education, it's designed to cut costs," she said.
But Gruff Hughes, deputy general secretary of UCAC, the Welsh-medium teachers' union, which did not sign the workload agreement, said national criteria for awarding TLR payments could benefit primary teachers.
"In primary schools, the number of management allowances is limited because of funding. Some teachers take on curriculum responsibilities but they don't get the allowance because there is no money for it. If there are national criteria, they will have to get it."
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