The Irish Nurses and Midwives Organisation (INMO) has warned that the HSE's €26m plan to deal with increased winter demand on the health service will not have an impact without extra staff.
The HSE yesterday published its winter plan for 2019 and 2020 to prepare for and manage pressure on services in their areas this winter.
It said that acute hospitals are continuing to see a year-on- year increase in the numbers of patients requiring treatment and care.
By the end of October, 1.1 million patients had attended its 29 emergency departments, which is 3pc more than the same time last year.
It said that its winter plan, supported by the allocation of an extra €26m to the end of the year, seeks to support improved patient care in hospitals and community healthcare organisations.
It prioritises helping patients avoid admission, providing care for patients in the community and minimising the time patients need to stay in hospital.
"We are focused this winter on ensuring patients are provided with the appropriate care to meet their needs as quickly as possible," said HSE chief operations officer Anne O'Connor.
''Building on lessons learned from last winter, we will have a number of initiatives with a particular focus on the timely discharge of patients from hospital to appropriate care in the community, including home care, step down/transitional care or long-term care."
However, the INMO said in response to the winter plan that while extra funds were welcome, the ongoing recruitment pause means that it is impossible to staff any additional services.
The union pointed to extra community services as vital to reducing hospital admissions, but questioned where the staffing would come from.
Speaking about the plan, INMO general secretary Phil Ni Sheaghdha said: "It's a simple case of too little, too late.
"Even setting aside winter, the health service is severely understaffed.
"The annual winter surge is entirely predictable, yet once again we are scrambling to plug the gaps in mid-November. It simply isn't good enough.
"The HSE need to drop their recruitment pause and ensure safe staffing levels across the health service."
Green Party health spokesperson Dr Seamus McMenamin said: "The HSE winter plan does nothing to address the structural problems in the HSE which lead to overcrowding in our hospitals and is at this point like moving the deckchairs on the Titanic."