The leadership of the Association of Secondary Teachers Ireland has accused the union's former president, Ms Bernadine O'Sullivan, and other activists of "personalised attacks". The move underpins running divisions within the ASTI.
The union's general secretary, Mr Charlie Lennon, and its president, Ms Catherine Fitzpatrick, say that the goal of a pay increase for teachers "seems to have been lost in a welter of accusations, personal attacks and self-justification" by the authors of documents circulated recently.
Their comments have been issued to members in response to strongly-worded criticisms by Ms O'Sullivan in a briefing document for those attending next week's annual convention. The ASTI leadership says it also wants to respond to a document circulated anonymously to schools earlier this year.
Mr Lennon and Ms Fitzpatrick write: "While it is with reluctance that we, as officers, respond to these personalised attacks, members of convention are entitled to a reasoned reply to the statements because they contain factual misinformation, selective narration of events, omissions which serve to distort and, in total, amount to a rewriting of history."
Ms O'Sullivan is not explicitedly mentioned in the leadership statement but it does specifically refute a range of charges made on her website this week.
The statement by the leadership reflects their growing exasperation with the tactics of Ms O'Sullivan and others within the union. Earlier this month, the INTO general secretary, Senator Joe O'Toole, said that the ASTI was controlled by a "clique".
The leadership denies any responsibility for the union's failure to build a joint strategy with the other teaching unions.
Mr Lennon and Ms Fitzpatrick also dispute the view that a pay increase could only be pursued outside the ICTU. "It is not true to say that a pay increase could only be pursued outside of ICTU. The Irish Nurses' Organisation, the Psychiatric Nurses' Organisation and SIPTU jointly negotiated a substantial restructuring claim for nurses while remaining within ICTU. Indeed, ICTU officers and officials actively pursued a settlement for these unions."
On supervision and substitution, the leadership refute the charge that two officers attended talks on the issue in apparent defiance of union policy. "The ASTI was not involved in negotiations on the supervision and substitution claim either inside or outside Conciliation and Arbitration until the Central Executive Committee (CEC) gave its approval."