The NUT will reveal this week whether it will stage a series of one-day strikes which would trigger widespread school closures in the run-up to Christmas.
200,000 NUT members have been balloted on whether they are prepared to take "discontinuous strike action" in opposition to the government's plans for below-inflation pay increases. The strike ballot closes today, with the leadership meeting later in the week to consider the result.
It follows a one-day strike in April which resulted in 2 million state school pupils being sent home for the day. If members vote for action, today's ballot would license the union to repeat the action nationally and in one-day strikes in single local authorities.
The union is demonstrating against a three-year pay deal worth 7% (2.45% in the first year and 2.3% in the following two) which it says has been eroded by increases in the rate of inflation, which is now running at 5.2%. As a result, teachers are up to £2,000 out of pocket as they face rising fuel and food costs.
The move was backed unanimously within the leadership of the NUT. In the ballot preceding the April strike, 32.2% of members returned votes, of which 75.2% were in favour of the action.
But there were anecdotal reports that members who had not been moved to vote before April's action, but then felt inconvenienced by the school shutdowns, might vote against the action this time. Union officials are also unsure of what impact the economic downturn could have on teachers, who would also forgo pay on strike days, leaving them short of money in the run-up to Christmas.