The National Union of Teachers executive has voted to ballot members over strike action in protest at a planned rise in the pension age from 60 to 65.
But doubts remain over whether the union will take action on the issue.
Members of its four-strong officers' committee were due to meet Steve Sinnott, the general secretary, yesterday to decide how to act following last week's executive decision.
A call by left-wing members to ballot for a one-day strike, to coincide with likely strikes next month by support staff unions, Unison and the Transport and General Workers' Union, was defeated. Instead, in a compromise, the executive voted to ballot on strike or unspecified "non- strike" action before Easter.
But there is disagreement among executive members over whether they were voting for a consultative "indictative" ballot or a formal official one.
Left-wingers fear that if it is interpreted as the former then it will be impossible for action to take place before Easter. Any action afterwards could clash with an expected May general election and they fear it might not happen at all.
Centre-left members stress that whatever happens the NUT will continue to campaign against the changes.
The TG announced this week that it would ballot its local government members over a national pensions strike, likely to take place on March 23, the date pencilled in for a possible Unison strike.
The other two main classroom teachers unions will not join the joint action but have not ruled out eventual strikes.