Leftwingers are angry because the union's leadership has recommended that the no-cover action be suspended. They say they will try to amend the motion on workload. This calls for an independent inquiry like that of McCrone in Scotland - which led to a 35-hour week for teachers and a 23 per cent pay rise over three years (see box, right).
The motion has already been agreed by the Association of Teachers and Lecturers, and is due to be debated next Wednesday by the National Association of Schoolmasters Union of Women Teachers at its annual conference in Jersey.
NUT general secretary Doug McAvoy said anyone seeking to amend the motion would "destroy the concept of joint working".
Peter Smith, ATL's general secretary, said any variation in wording between the three main unions and the Welsh UCAC would make it "very difficult to consider such a coalition again".
Continuing with industrial action when the Government had agreed an inquiry would be futile, he added.
But NUT leftwingers, angry that the action may be suspended without a vote at conference, are planning their next move.
Martin Powell-Davies, Lewisham NUT branch secretary, said: "The Socialist Teachers' Alliance will be meeting at the weekend to decide our strategy, but we expect to try to amend the motion. We are in favour of united action, but are dubious that anything substantial will result."
Ian Murch, the NUT's national executive member for West Yorkshire, said people had originally not wanted to interfere because the motion was generaly positive. But the decision to suspend the action had changed this. He said: "Teachers are in a strong position because of the election and the recruitment crisis.We want a bit more than just talks about talks to suspend the action."
Meanwhile, the Government has made it clear that a McCrone-style agreement is not on the cards.
Education Secretary David Blunkett's political adviser said the union was demanding the equivalent of the average British worker doing a 30-hour week, which was "not likely to be on the agenda".
He said: "But, if there is no action taking place, we are prepared to look positively at a review of workload issues. There are plenty of practical steps we can take."
WHAT THE SCOTS GOT...
THE MCCRONE DEAL:
* 10 per cent pay rise this year, and 23 per cent by 2004.
* Contractual working week of 35 hours plus guaranteed 22.5 hours contact time, to be phased in over five years.
* 4,000 extra teachers by 2006.
* 3,500 more support staff by 2004.
* No performance-related pay.
* No loss of holiday time.
* New "chartered teacher" grade allowing those who stay in classroom to earn up to pound;6,000 extra.
* Top earnings for classroom teachers will rise from pound;25,644 to pound;28,707 by 2003.
* New framework of continuing professional development by 2003.
* Scots are paid less than the English and Welsh - and won't catch up till 2003,at the earliest.
* Automatic time limits on specific duties go in 2006.
* Teachers are expected to work more flexibly.
* They will do 35 hours a year extra professional development.
* The career structure will change and some senior teacher posts will be abolished.