The trade union IMPACT is to introduce a ban on co-operation with the Government's healthcare reforms from Monday in a move which it maintains will make the process inoperable.
Under the industrial action IMPACT members will withdraw from the change management teams currently run by the interim Health Service Executive.
They will also refuse to co-operate with drawing up national service plans when the full Health Service Executive comes into operation from the beginning of January.
The national plans, which are key blueprints for the development of services, are the main responsibilities of the new executive.
IMPACT's national secretary, Mr Kevin Callinan, said last night that members wanted safeguards over service continuity, jobs and working conditions when the new health structures came into force.
In a statement last night the union said that a meeting of its health division executive considered new proposals from employers, but believed they fell short of what was needed to avoid the dispute.
Mr Callinan said that a document provided by health service managers provided "a set of principles" rather than the details that members sought.
Last week the Government appointed the former president of the Irish Congress of Trade Unions, Mr Phil Flynn, to facilitate discussions between the two sides, and this process is expected to continue for the moment.
Meanwhile it emerged yesterday that the country's health boards, which were scheduled to be abolished in a fortnight, will continue to run existing services for several months.
However, they will not be allowed to establish new or additional developments.
The Department of Health yesterday sent letters to the health boards allocating funding for next year.
However, the letter is understood to instruct the boards to operate on "an existing level of service" without introducing new developments.
The Department said last night that the Health Service Executive would take over the assets of the health boards from the beginning of January and would draw up national service plans, which would provide for the introduction of new services.
In a separate development last night, the Minister for Health, Ms Harney, announced the appointment of Mr Liam Downey as chairman of the Health Service Executive.
Mr Downey has served as a member of the executive since it was established. He is a former chief executive of Becton Dickinson Ireland, a medical technology company.
He was president of the Federation of Irish Employers and a trustee and member of the National Executive Council of the Irish Business and Employers' Confederation.
It was also confirmed last night that the former chief executive of the Food Safety Authority, Prof Patrick Wall, has been appointed acting health adviser to the executive.
