The head of the HSE has written to staff to ask them to volunteer to work over the June bank holiday weekend.
Bernard Gloster asked staff to take on extra shifts to avoid a "dreadful position" in hospitals following previous holiday weekends.
He said further overcrowding would have "implications for the rest of the healthcare system".
Speaking in Galway on Thursday, Mr Gloster said hospital managements around the country would be starting to ask staff over the coming 24 hours to alter their work arrangements that weekend to allow service provision to be closer to weekday levels.
He was addressing delegates representing some 33,000 workers at the Fórsa trade union’s health division conference.
The request, Mr Gloster said, would be to work on a voluntary basis with those making themselves available receiving either overtime payments or days in lieu in accordance with the terms of their contracts.
In the longer term, Mr Gloster said a move to seven-day rosters for a whole range of HSE staff outside the ranks of doctors and nurses was essential if capacity issues were to be addressed and services improved. It would, he said, be a key issue in the forthcoming public sector pay talks.
“The reality is we have exceptionally talented, very good people working across the Irish health service but the majority of our working practices and processes by which people move through the system are Monday to Friday and at the weekends it’s essentially medical on-call care and nursing care in our hospitals and in our community services and GP out of hours.
“We need to put a whole range of services around them at weekends to keep people moving through the system. That won’t make it perfect, but it would certainly reduce some of the significant pressures that the public are experiencing.”
Responding to the proposals, Ashley Connolly, Fórsa’s head of health and welfare, said there had already been a succession of requests this year to work additional or different hours and that the union had no issue with that as long as people had a choice. Beyond that, she said, the union would engage on any proposed reforms.
A spokesperson for the Irish Hospital Consultants Association said it welcomed Mr Gloster’s “recognition that the significant capacity and resourcing challenges facing our hospitals must be immediately addressed and echo his comments that a whole-of-service approach is required to do this.”