The Irish Hospital Consultants Association has said that having around 28 hospital emergency departments open 24 hours a day is no longer sustainable or safe.
IHCA President Dr Denis Evoy told the group's annual conference in Kildare that the number of emergency departments open 24 hours should be cut by half to around 14.
He said the other departments could operate on a 12-hour basis.
Dr Evoy said this would also help end excessive shifts for non- consultant hospital doctors.
He accepted that it could be politically difficult to implement and the public would need to be reassured that the change would deliver better care and services.
The conference also heard that 20% of consultant posts are either vacant, or filled on a temporary basis.
Consultants say there is a haemorrhage of doctors to the US and Australia, in particular due to pay cuts, hospital conditions and unrelenting budget cuts.
The IHCA said that further cuts in the health budget are expected next week, despite the fact that €1bn has been taken out of acute hospital budgets since 2008.
Dr Evoy said that the Health Service Executive was currently driven by Troika demands and budgetary constraints, rather than welfare and patient safety.
He said the HSE can be very unsympathetic and stubborn, traits that can demoralise a workforce, or radicalise it, as evidenced by the junior hospital doctors' strike last week.
HSE National Director of Acute Hospitals Ian Carter told the conference that if the system keeps taking money out of the health service, there will be further dysfunction.
He said that since 2008, around 22% has been cut from the HSE budget and much of the cutting has been done crudely, purely for fiscal reasons.
Mr Carter said that the idea that by taking more money out of the health service you tackle inefficiency is wrong.
He said that hospital managers must be accountable but that there must also be robust accountability for consultants too.