The teacher unions would be better off uniting and fighting their case alongside other public-sector workers, the senior trade unionist, Mr David Begg, told the TUI conference.
Mr Begg, general secretary of the Irish Congress of Trade Unions (ICTU), appealed to the ASTI to consider re-joining congress, which they left over two years ago. "If they do desire to re-affiliate, I, for my part, will do what I can to smooth their path," he said.
Speaking after his speech he said it was "absolutely disastrous" for the ASTI and the teaching profession generally that the pay dispute had gone on so long. He said it might be time for the ASTI to "step back a little from where they are".
"The best results are not going to be achieved with a divided union movement," he said.
In a well-received speech, he told delegates that bringing benchmarking to a satisfactory conclusion remained the major challenge facing public-sector unions in the coming year. "It would, I think, have been better if we could have approached the task with a united teaching profession."
Referring to the ASTI position, he said: "In dealing with any industrial problem it can be helpful to maintain a clear distinction between principle and strategy. It is when strategy gets elevated to the status of principle that the real problems begin."
Meanwhile, the vice-president of the union, Mr Paddy Healy, circulated a document warning of a threat to public service pensions. He said the threat was contained in the Commission on Public Service Pensions which would be implemented when the PPF expired.
He said the use of a new "index" to decide on pensions was not suitable for the profession. It changed the practice which has been in place for 30 years that public-sector pensioners get the same percentage increase as serving workers. However, TUI general secretary, Mr Jim Dorney, said the use of the index and its impact "remains to be determined".