In a dramatic escalation of its dispute over supervision, the ASTI is to ballot its members for a second time on the issue.
The decision means plans by the Department of Education to introduce the new supervision arrangements in secondary schools will have to be abandoned - for now.
Most parents are unlikely to notice any real change, as the contingency plan which has been in place since last March will con- tinue. This involves use of non-teaching personnel to take super-vision and substitution duties.
Two months ago, ASTI members voted 60-40 to accept the Department of Education's €37 an hour deal. The vote appeared to sound the death knell for the ASTI's three-year campaign on pay and other issues.
Last night however, a motion calling for a new ballot in the name of the national organiser, Mr Noel Buckley, and the treasurer, Ms Patricia Wroe, was backed by 19-3.
During the meeting, some members said teachers had been misled about the scheme's operation in the run-up to the first ballot late last year. They were misled, they said, into believing teachers would be paid for being "on call" for supervision, but the Department and management bodies insist teachers will only be paid for hours actually delivered.
Under the voluntary system, teachers are paid for 37 hours of supervision/substitution work a year - about €1,400 per annum - whether they perform those hours or not.
Under the deal, teachers are not allowed to do supervision/substitution for more than 90 minutes in any one week. Supervision payments are also pensionable. Until the deal, teachers received no payment for this work. The ASTI however claims teachers should be paid if, for example, they make themselves available for a 40- minute supervision period.
A fresh ASTI ballot could trigger new internal divisions. Some who voted for a new ballot blame the leadership for confusion; the leadership says it did not know about the lack of provision for "on-call" payments until contacted by school management bodies after the November ballot.
Some in the leadership see the current dispute as having little to do with the operation of the scheme per se. Instead, they say it is an opportunity for some members to renew their attack on the leadership.
The Minister for Education, Mr Dempsey, is understood to be determined not to give ground to the union.
Last night, Mr George O'Callaghan of the Joint Managerial Body (school managers) expressed disappointment at the ASTI's rejection of a "fair and flexible" scheme.