The level of opposition became evident during a meeting at NUT headquarters at which Sandy Adamson, the senior civil servant concerned with the zones, met the union's local representatives.
A show of hands revealed that two-thirds of the NUT representatives who work in action zones had still to make up their minds. But Mr Adamson was able to allay some of their fears.
Earlier in the meeting he had been told that members were concerned because classroom teachers had not been consulted and in many cases governing bodies had not held a full meeting to discuss the bids before they were submitted to the Department for Education and Employment.
The local education authorities leading the bids were blamed for the lack of consultation, but it was also agreed that the very early deadline for bids had made debate difficult.
The meeting also heard from Graham Lane, education chair of the London borough of Newham, which intends to introduce a five-term year in its zone.
Doug McAvoy, general secretary, said: "There was a range of attitudes, from very anxious to relaxed. There was concern that classroom teachers had not been consulted in the first bids, and it was agreed there should be a greater effort to involve them in the partnership. The members were also assured that the union will provide full protection if there are any signs that pay and conditions are worsened in the zones.
"Many of the two-thirds were genuinely neutral and said it was the first time they had been properly briefed. A large number said they felt more reassured. "
The first 12 zones are expected to "go live" this September, but the Government will be hard-pushed to reach its deadline. Many of the zones still have to set up forums to run the schemes and have to appoint zone managers.