A North Yorkshire NHS trust is to axe 600 jobs - a third of its workforce - to try to save £10m, staff have heard.
Managers from the Scarborough and North East Yorkshire NHS Trust gave the news to staff on Wednesday.
Unison regional officer Ray Gray said the redundancies were a "disaster" for health services in the area.
Ian McInnes, the Chief Executive, said the cuts would not affect the A&E department and their main priority was that patient care did not suffer.
It comes off the back of a series of jobs cuts across the NHS in England in recent years as health bosses have struggled to balance the books.
Latest figures from the NHS Information Centre show that 17,000 posts have been closed in the last 12 months alone.
However, this has only amounted to about 1,500 compulsory redundancies as trusts have imposed recruitment freezes.
The North Yorkshire trust runs Scarbrough General and Bridlington District hospitals.
The trust was established in 1992 and covers one of the largest geographical areas in England.
Chief Executive Ian McInnes said that although the remedy was drastic, making people redundant was an unhappy responsibility and there would now be a period of consultation.
Unison's Ray Gray said: "Job losses on this scale are completely unsustainable. It would devastate the NHS in this part of Yorkshire and have a profoundly damaging effect on the local economy.
"How the trust has ended up in this dire situation is a matter of grave concern and we are seeking urgent talks with the Secretary of State for Health to find a way of saving the jobs and the health service in the Scarborough district."