Fianna Fáil leader Micheal Martin has said he is preparing to be Taoiseach and has accused the Government of "playing around with people's health and lives".
Mr Martin said Fine Gael had "gone very right wing" and ruled out going into coalition with that party.
Asked if he was preparing to be enter government after the next election, he replied: “I am preparing to be Taoiseach”.
He was being interviewed on RTÉ Radio One's Morning Ireland programme this morning.
He called for a transparent approach to the budgeting of health because, he claimed, the Government could not be trusted.
“No-one said on Budget day we are going to crucify you on health. No-one said we are going to risk patient safety,” he said.
“They are playing around with people’s health and lives here.”
Speaking on Newstalk later, Mr Martin said going into coalition with Sinn Féin was not an option for his party.
Asked if Fianna Fáil would coalesce with Labour, he said the local elections had shown that the political system was fragmented.
“It’s up to the Irish people...People are fed up of commentators going on about the numbers game and percentages,” Mr Martin said.
Minister for Transport Paschal Donohoe later rejected Mr Martin’s suggestion that Fine Gael had become a “right wing” party.
Mr Donohoe said Fine Gael was a party “of the centre” when responding to Mr Martin’s ruling out of his party as a potential coalition partner for Fianna Fáil.
“I find it very rich Micheál Martin is talking about this when his was the party of light-touch regulation and bringing in tax cuts and tax breaks that the country couldn’t afford then and can’t afford now,” Mr Donohoe said.
“I’m struck at the moment Micheál Martin appears to be ruling out just about everybody to participate in Government the next time round.”
Mr Donohoe said his “overwhelming preference” would be to see the current Fine Gael/Labour coalition re-elected. He was speaking in Dublin at the launch of a Tourism Ireland strategy to boost tourist numbers from Canada.