Nurses at Beaumont Hospital in Dublin are urging the HSE to take it off call.
Members of the INMO say that 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 appealed for the HSE to allow staff bring the situation under control.
“The hospital is in crisis since Monday yet the appropriate actions have not been taken to address the severe overcrowding levels,” she said.
“It is imperative that the hospital goes off call immediately and remains off call until such time that the situation is brought under control.”