A significant number of ASTI members have come out strongly against the revised Labour Court package ahead of the union's annual conference next week.
At regional information meetings last week most members reacted negatively to the package, according to union sources.
Most objected on the basis that it did not contain an "upfront" salary increase. The proposals were most strongly criticised at Dublin meetings.
The regional meetings are for school stewards, members of ASTI's central executive council and branch officers. These members are regarded as especially influential in the union.
The payment of £1,750 for finishing the Leaving and Junior Cert courses was also received negatively at the meetings. And the plan to give teachers a £350 annual grant towards a computer/software was derided.
Despite the negative reaction some union sources say other members who are not as closely involved in union activity may be more supportive.
Some ASTI members are also worried that if the union does not enter the benchmarking process its case may not be represented properly by the leaders of the other unions.
Mr Charlie Lennon, general secretary, said the union's members were still considering the package and the regional meetings were important in clarifying several matters.
Balloting of its 17,000 members takes place at the end of the month and a result is expected in early May.
The union's annual conference in Galway is expected to be an angry affair, with the Minister for Education, Dr Woods, likely to face a hostile reception. Some ASTI members are planning to register a protest during his speech.