Teachers knew they could not have a significant increase in salary because of the financial crisis facing local authorities, Peter Andrews, the institute’s salaries convener and staff leader of the Scottish Joint Negotiating Committee, said.

Replying to a West Dunbartonshire motion calling for industrial action to support next year’s pay claim, Mr Andrews admitted: “The last few settlements have been disappointing in levels of award but they have been accepted by the membership as the best we can achieve in the present climate.”

Members were more interested in preserving conditions of service and tackling issues like class sizes.

But following four years of failure by left-wing delegates to demand action if negotiations did not produce a satisfactory pay outcome it was fifth time lucky for Elaine Murray, Edinburgh, who asked: “How can this be a hollow tactic when we have never tried it?” Members were disillusioned by the union’s failure to fight cuts, redundancies and low pay. “It is time to stop feeling sorry for local authorities and start pushing them,” Ms Murray declared.

Delegates backed her by 146-130 votes, but the leadership believes it can live with the decision.

Earlier, Mr Andrews, who is standing down as salaries convener after seven years to be replaced by Malcolm Maciver, pointed out this was the third consecutive year the Government had failed to make an allowance for teacher pay rises but never the less teachers had won a higher settlement than other local authority workers.

They had virtually equalled the teachers’ settlement south of the border without any deterioration in conditions. For the past nine years, salaries increased slightly above the rate of inflation due to goodwill on the negotiating committee.

The traditional left-wing plea for “flat-rating” of salary increases to remove differentials was again defeated by 181-138 votes. Mr Andrews emphasised the majority of Scottish teachers were already at the top end of the scale.