Chief Executive of the Health Service Executive Bernard Gloster has said seven day provision of healthcare is central to the effort to improve services across the country.
Speaking at the Fórsa Health and Welfare conference in Galway, Mr Gloster said there was "incontrovertible evidence" that the level of staffing at weekends and public holidays was below what was needed by the public.
He asked delegates to assist in the move to distribute services more evenly across the full week.
Citing the example of the May bank holiday weekend, Mr Gloster said hospitals had been left in an "absolutely dreadful position" as a result of backlogs over the course of the three days in question.
To try and avoid a repeat of this, he is asking hospital group CEOs to request that certain grades work on the June bank holiday weekend.
Mr Gloster told the conference that such change would be challenging but that it was necessary.
He said he hoped existing staff would respond positively to the request, saying "we have to distribute what we have more evenly across the week".
And he signalled that future contracts will have to operate on a seven day basis.
He said that in future negotiations on public sector talks, he would be proposing that distribution of service over seven days would be as important as anything to do with the structure of the organisation itself.
Fórsa Health and Welfare Divisional Head, Ashley Connolly, said any proposed changes to work practices would have to be subject to detailed discussions.
She said her members had demonstrated a willingness to put their shoulders to the wheel and would not shy away from reform.
However, she said the union expected that its voice "would be heard and listened to".
There is a lot of fear around "one liners being announced" with no real detail around how proposals would operate, Ms Connolly added.
"This will generate a level of fear and we will need extensive engagement ... this can't just be something that is rushed."
