Paramedics who are members of the Psychiatric Nurses' Association will protest at Leinster House later, demanding the HSE recognise their union.
They plan to strike for 24 hours starting at 7am on July 19 in the eighth day of industrial action in their campaign.
Tony Gregg, secretary of the PNA paramedics' branch, said the right to decide what union to join belongs to the worker, not an employer.
Mr Gregg said: "We're protesting outside Dáil Eireann to demonstrate our determination to ensure that paramedics will never surrender the right to the Government or an employer to choose a union of their choice.
"As far as we are concerned, that's a right specific to the worker."