The latest resignation from Sláintecare is creating 'a standoff' in the health system.
That's according to the Irish Patients' Association, which says Professor Anthony O'Connor's departure from the Implementation Advisory Council means 'someone needs to take the reins'.
Prof O'Connor said on Thursday he was quitting because of his disappointment with the pace of the health reform plan.
Two other members stood down earlier this month, but the Government says it remains committed to the project.
Sláintecare executive director Laura Magahy and chair of the Implementation Advisory Council, Professor Tom Keane, both resigned their positions in September.
Stephen McMahon, director of the Irish Patients' Association, told Newstalk Breakfast this puts the porgamme in a bad position.
"I think it was expected that there would be further resignations, and who knows what'll happen over the coming weeks.
"We are now four weeks into this crisis about the future of our healthcare system.
"And we now find ourselves that there appears to be a sort of a standoff between the existing establishment - the HSE, perhaps the Department of Health - and the people who are charged with reforming the system.
"We did learn last night that Laura Magahy and Prof Keane had met the Taoiseach earlier this week, and I understand that that meeting was very constructive.
"But really we have to get to grips with this".
Consensus 'beginning to splinter'
He says this is undermining morale, as well as delaying access to care with "almost 700, 800,000 patients waiting to get access to our care... and this is all being delayed now".
And he says the consensus around the plan is fading.
"Lets recall here that this was a political consensus, probably the first time we had such a thing in Irish politics.
"They agreed on a strategy, and the funding and all the other things to do with that.
"And now we find that that's beginning to splinter.
"Someone needs to take the reins here in the interest of patients, and indeed our wider public, to ensure that these parties get together."
While former head of the HSE Tony O'Brien has said the reform plan needs to be moved away from the Department of Health.
Speaking last month, he said: "One of the key recommendations that this all-party Sláintecare committee came up with about where this thing should sit, where it should be controlled from, was disregarded under the previous government [and] that's continued under this one.
"But because this is a new Government, with these dramatic - some might say unprecedented - resignations, it does create an opportunity for that to be reviewed.
"So should this sit within the Department of Health, or should it sit at a higher level within Government - reflecting the significant priority?
"This doesn't have the authority or the direct oversight of the Department of the Taoiseach, it's located in the Department of Health.
"And one of the challenges about that is there is historically ambiguity about the relative roles of the Department of Health and the HSE."