The future of Sláintecare hangs in the balance following the resignations of two senior officials.
Its Executive Director Laura Magahy and Chair of the Implementation Advisory Council Professor Tom Keane have both stood down.
The Sláintecare reform programme was established to end private practice in public hospitals and to cut waiting lists.
Health Editor with the Irish Times, Paul Cullen, says the resignations are a significant development.
'It certainly raises big questions about the future of the programme.
"There have been questions about Sláintecare for the entirety of its existence.
"It's a ten year programme, it's already year four and let's face it, not all that much has happened, or at least not much that is visible, and hertainly not much in the main area that the public would be aware of which is getting rid of waiting lists.
"In fact, things have gotten worse."
