Tánaiste Frances Fitzgerald has said it was "absolutely unacceptable" that hundreds of patients are waiting on trolleys in hospitals, as a hospital consultant warned 350 people could die needlessly this year.

There were 601 patients on trolleys or on wards waiting for admission to a hospital bed yesterday, according to the Irish Nurses and Midwives Organisation.

It was the third highest figure so far this year.

Ms Fitzgerald said it was "absolutely unacceptable to all of us that hundreds of patients are on trolleys for long periods of time, especially for those patients who are elderly and vulnerable".

"It also makes for extremely difficult working conditions for front line staff".

She said that Minister for Health Simon Harris was determined to tackle overcrowding, and that three key measures were under way to do so: a bed capacity review, recruitment and new GP contracts.

Earlier, a spokesperson for the Irish Association for Emergency Medicine warned up to 350 people will die needlessly if things do not improve in the Irish health service over the next year,

Speaking on RTÉ's Morning Ireland, Dr Fergal Hickey said the key issue, that there is a shortage of beds, was not being addressed.

The estimates by Dr Hickey are based on two studies carried out in other countries in 2006.

The studies are very accurate and have never been contested, he said, adding that if the figures are applied to an Irish population, then an estimated 350 deaths will occur.

There are up to two needless deaths every year in his emergency department in Sligo, he said, and it is the same in other emergency departments across the country.

He said he has had to apologise to families for their poor experiences in the emergency department that have resulted in poor outcomes.

There was a shortage of beds before austerity and that more have since been removed from the system, he said.

At a minimum, he said, 2,000 beds needed to be re-opened.

The highest number of patients waiting for admission for a hospital bed ever recorded by the INMO was 612 patients waiting on 3 January, while 602 patients were recorded waiting on 4 January.

Figures from the Irish Nurses and Midwives Organisation, which also count the number of patients on wards waiting for admission to a bed, show 517 patients on trolleys today.

Meanwhile today, HSE figures show there are 393 patients on trolleys. 

The 'TrolleyGar' figures represent a 26% increase on this day last year.

The hospitals worst affected are Tallaght with 47 patients on trolleys, Galway University Hospital with 37 patients waiting and St Luke's Hospital Kilkenny with 29.