NIPSA has been blasted for its failure to give assurances that pupils with special needs will not be caught up in any further strike action.
In an interview with the Belfast Telegraph, chief executive of the Southern Education and Library Board Helen McClenaghan hit out after the public service union refused to say whether it will implement measures to ensure children with special needs can continue going to school during any industrial action by its members.
And she revealed that, according to legal advice, which she said has also been given to the unions involved in the dispute, the Education and Library Boards cannot retain the 32.5-hour week but she stressed that no classroom assistant currently employed will lose any money as a result of accepting the offer.
However, general secretary of Nipsa John Corey last night said the union had been told by its legal advisors that the retention of the 32.5-hour week is the contractual entitlement of all existing classroom assistants.
"The employers are claiming they have legal advice that says they can't apply the 32.5-hour week but that is contradictory to what we have been told," he said.
Mrs McClenaghan also said she was angry and frustrated that members of Nipsa are not being given the opportunity to express their opinion on the latest offer by management - which, if accepted, would mean that classroom assistants in Northern Ireland will be among the best paid in the UK.