The Irish Nurses and Midwives Organisation has said there are more than 1,300 nursing and midwifery posts left vacant in Ireland's acute hospitals because of a ban on recruitment.
The INMO said 7% of funded posts were vacant, with 1,251 vacancies out of more than 17,600 posts.
The figures show 66 unfilled nurse and midwife management roles.
The INMO also reported 420 vacancies in community health services, which cover care of the elderly, public health, and intellectual disability.
INMO General Secretary Phil Ní Sheaghdha said: "The figures are stark. The Government are refusing to fill frontline healthcare posts.
"Make no mistake, this will lead to compromised patient care and staff burnout."
Speaking in RTE's Today with Miriam, she said more than 1,500 nurses graduated this year, and according to INMO figures, less than half of them have been promised a job, but contracts have not been issued yet.
"They need to have a contract, they need to know they're going to be employed because the offers from Britain are too good to turn down in many instances. And therefore we have negotiated better salaries for this graduating group, that has just been confirmed that those salaries will be available.
"However they need the contract. They need the job," she said.
Ms Ní Sheaghdha said the recruitment ban is not cost saving because the money is already there.
"These posts have become vacant and when a post exists it has to have funding attached to it
"What the HSE will now be forced to do is engage agency to maintain the basic level of care that is required, that costs a lot more and then in six months or a year's time we'll be back within a massive overspend on overseas recruitment."