Educational psychologists are planning widespread industrial action in protest at years of deteriorating pay and conditions.
A list of more than 20 actions which constitute working to rule is being drawn up by the leadership of the Association of Educational Psychologists, ready to be sent out to members in the new year.
And the association now looks almost certain to quit the National Union of Teachers in protest at what it sees as the NUT's failure to back the AEP's claim for substantial pay rises in recent years.
Educational psychologists say they have watched the erosion of their pay and conditions in frustration, despite being in a "sellers' market". The AEP claims there are empty posts in two-thirds of local authorities, which cannot quickly be filled as it takes seven years to train an educational psychologist.
The work-to-rule suggestions - which have yet to be ratified by the association's executive - are likely to be circulated to members in the new year, well before the 1998 pay negotiations. It will be left to members to decide whether or not to follow them.
Suggestions include "obeying the Highway Code". Many educational psychologists drive considerable distances - the association will suggest members resist the urge to break the speed limit in their rush to attend meetings. AEP officials believe all the suggestions are legal and will not put members' jobs at risk. But the action is likely to receive short shrift from employers.
Graham Lane, chairman of the Local Government Association education committee, said: "These psychologists need a lesson in the psychology of industrial relations."
General secretary Brian Harrison-Jennings said: "This is an attempt to stem the continuing deterioration of our working conditions."
Educational psychologists need a psychology degree, a postgraduate teaching qualification, two years' classroom experience and a master's degree. But they say their pay has failed to keep pace with teachers', with differentials eroded by 17 per cent in the past 10 years.
Casework has grown and members spend increasing amounts of time on bureaucracy and assessing pupils for statements of special needs instead of helping teachers develop strategies to improve classroom behaviour and prevent problems. They also complain that accommodation has grown more cramped. Many work in open-plan offices which means sensitive casework cannot be done in privacy.
But there was some disquiet among members at a fringe meeting with Mr Harrison-Jennings at last weekend's annual conference - particularly at suggestions that members should take sick leave "on a co-ordinated basis so there is never a full complement of staff".
Sick leave was effectively exploited by British Airways cabin crew in a dispute earlier this year. Hundreds called in sick rather than officially going on strike. But critics of these tactics within the AEP said it was vital that members were seen to "maintain their professionalism". And Mr Harrison-Jennings said after the meeting that there was no suggestion that members should call in sick if they were not ill.
Mr Lane argues that educational psychologists' 2.95 per cent pay settlement last year was "the best in local government". Conditions had not worsened - employers had taken on more staff to cope with the increasing workload.
He accepted differentials had been eroded. "But teachers' pay is agreed by their pay review body and it has been funded by larger class sizes," he said.
The AEP believes it can afford to flex industrial muscle. It claims that 95 per cent of educational psychologists are members. And unlike youth workers or inspectors, with whom they jointly negotiate with employers via the Soulsbury Committee, these members provide a service that local authorities are required by law to deliver.