A health economist says he does not believe the proposed implementation of Universal Health Insurance is workable within the timeframe set out by the Government.
The White Paper on the policy is due to be published later this month, and a number of changes are understood to have beeen made to it at yesterday's Cabinet meeting.
The Government says it wants the scheme to offer a standard basic policy for every citizen and be rolled out by 2019.
However Professor Brian Turner of University College Cork said there are too many unanswered questions about what each standard policy will cover, and how much the scheme will cost.
He said "real reform" of the health sector cannot be achieved by any one government.
"Real reform in the Irish health system is going to take decades - not years, but decades," he said.
"It's going to take a number of different governments with a number of different political view.
"If we have an agreed framework for that, then as many governments as it takes will have a genuine mandate from the people to implement the reforms that the people want."