ACRIMONY threatens to engulf ministers' plans for performance pay after Britain's largest teaching union told members to consider formal action against heads if refused a pound;2,000 wage rise.
The National Union of Teachers says grievance procedures are the only option because the Government has failed to provide a right of appeal in its radical shake-up of teachers' pay.
It will also canvass members' support for industrial action including a one day strike.
Heads' leaders warned grievance procedures would be bound to fail and would create immense ill-feeling in schools. They urged ministers to close any loophole that might allow the process to be used. The advice is also likely to be unpopular with the NUT's numerous primary heads.
Teachers will be able to apply from late March to cross the performance threshold and win a pound;2,000 pay rise. Heads must rule on each application, with external assessors vetting decisions to ensure national standards are applied.
NUT general secretary Doug McAvoy said: "In the absence of any appeals procedure established by the Government, help will be given in using grievance procedures against their headteacher or, where the external assessor rejects the headteacher's advice, against the external assessor."
But David Hart, general secretary of the National Association of Head Teachers, said the use of grievance procedures was "out of the question". It woul undermine the assessors, create bad feeling and drag governors into an issue in which they had no expertise. It would also be impossible to take action against assessors since they were not employed by the school.
John Dunford, general secretary of the Secondary Heads Association, warned that action by teachers would "make the situation much more difficult".
"It is going to be hard enough for heads in the first year of operation. Nobody has any experience of the system - not even the people leading the training."
NUT left-wingers continue to press for tough action against payment by results, despite failing last week in their attempt to call a ballot on strike action before Easter. The executive ordered a survey instead to see how far members were prepared to go.
Options to be put in the survey include a one-day strike, a national demonstration, a lobby of Parliament, and a boycott of staff training in the new appraisal system which underpins the new pay structure.
The National Association of Schoolmasters Union of Women Teachers took its message direct to MPs this week, taking out a full-page advertisement in The House Magazine, the journal for the Houses of Parliament.
Chris Gale, chair of the National Governors' Council, said the NUT's suggestion of grievance procedures showed how muddled the threshold proposals had become.
Many governors would be unhappy at being dragged in. "It's something we have not been asked to do before," she said.