SIPTU has warned that thousands of healthcare staff working in State-supported voluntary organisations will stage strike action on 12 February in a dispute over pay.
Up to 12,000 staff, in what are known as Section 39 organisations, experienced public service pay cuts, but are not being given restoration in line with other workers in the health sector.
Speaking on RTÉ radio, SIPTU Health Division Organiser Paul Bell said there had been eight separate Labour Court recommendations upholding the pay link, but the Government had yet to act.
"Our members find themselves being caught in a battle between the department of health, the department of public expenditure and reform, the HSE and the section 39 organisations themselves," he said.
He said it has been a very frustrating period for the union’s members.
In a statement, Mr Bell said union members had done everything possible to avoid a strike, but they now believe it to be their only option.
"Our members have done everything possible to avoid a strike which would impact on some of Ireland's most vulnerable citizens," he said.
He added: "Unfortunately, due to the actions and inactions of Government and the individual Section 39 employers they increasingly believe that their only option is strike action."
The union also said it has made an application to the Joint Oireachtas Committee on Health for a hearing in January over pay for Section 39 organisation workers.