The HSE chief is to meet with the Health Minister later for an update on emergency department overcrowding.

The number awaiting hospital admission on trolleys has surged past 600 on two days this week.

SIPTU is raising concerns about the knock on effects for ambulance workers, who they say are spending up to five hours waiting at hospital Emergency Departments.

SIPTU's Health Division Organiser Paul Bell, says the public needs to be aware of the situation: