Nurses at Beaumont Hospital in Dublin are urging the HSE to take it off call.
Members of the Irish Nurses and Midwives Union (INMO) say the emergency department is crammed far beyond capacity.
They say the facility is no longer safe - with 75 patients on trolleys there tonight, 33 of whom are awaiting an inpatient bed.
INMO Industrial Relations Officer Lorraine Monaghan is appealing for the HSE to allow staff bring the situation under control, saying the "hospital is in crisis since Monday".
473 people were on trolleys in emergency departments or still waiting on a bed this morning.
That was down 85 on figures yesterday, according to statistics from the INMO.
Maura Wynne is an emergency department nurse at Beaumont Hospital in Dublin.
She voted against the HSE proposals to deal with overcrowding.
The Health Minister Leo Varadkar says he is confident next week's planned industrial action by nurses at seven emergency departments can be averted.
Members of the INMO voted against proposals aimed at resolving overcrowding problems because they say they are not confident they will be implemented, on a 24-7 basis.
Representatives of 26 emergency departments will meet in Dublin tomorrow ahead of action next week.
Minister Varadkar says the resources are available to ensure the recommendations can be fully implemented.
"Certainly the resources are available to implement these proposals, we may not have resources to do other things. We certainly don't have the resources to do everything we would like to do in the health service in one year, but the financial resources will be there to implement these proposals".
The INMO General-Secretary, Liam Doran says his members were reacting to a crisis situation over the holidays, something he described as "devastating".
Rolling two-hour stoppages at seven hospitals are scheduled for Thursday of next week, with further action on 26th.
Liam Doran told Newstalk Breakfast earlier his members cannot accept a situation where more than 550 patients were on trolleys yesterday.
Minister Varadkar told the show he hopes talks with union representatives will provide the assurance nurses need that the new proposals will be implemented, so they will call off industrial action.
