The costs of compulsory health insurance will vastly overshadow the effect of water charges, Fianna Fáil has warned.
Micheál Martin used his opening speech at the party's Ard Fheis to criticise the Government is record on health, and said the government plans to privatise the entire health service.
He said the Government's plans for universal health insurance will hit the average family hard, and the more the Government is challenged on it, "the more photo opportunities [they] schedule."
"If you think Irish Water is bad – if you think water charges and the property tax are unfair - just wait until you see the stark reality f the bill for their compulsory private health insurance plan," he said.
Earlier, Fianna Fáil said it is ready for government, and ready to offer an alternative to Fine Gael and Labour, as Martin told attendees that the death of the party is still a long way off.
"Four years ago, most commentators predicted we were finished - something they often forget. But we are, again, the largest party in local government.
"And whenever Enda Kenny finally decides to go to the country, we will be ready for him."
Up to 3,000 members are expected at the Ard Fheis, each of whom will have a vote to elect the party's next leader after changes agreed last night.