Fianna Fáil's Health Spokesperson Billy Kelleher says the €1bn target for Health Service savings next year isn't "credible" or "sustainable".
Last night it was confirmed that the HSE will have overspent by €351m by the end of this year - and it will receive a €219m bailout once once it's been voted on by the Dáil next week.
That's on top of the €666mo in savings earmarked in Budget 2014.
Deputy Kelleher said the Health Service simply cannot make those cutbacks - and patient care could suffer as a result.
"The budget that they presented to the Dáil was never going to be sustainable," he said.
"I think it's disengenuous, to say the very least, to say that we can actually fund health services in any meaningful way next year and still find €1bn in savings.
"It simply isn't credible."