Key NHS services in Lincolnshire could be moved from Boston and Grantham to Lincoln in a bid to save money, according to a leaked memo.
Proposals in the memo addressed to some staff at Boston's Pilgrim Hospital mean night time accident and emergency services could be reduced.
The United Lincolnshire Hospitals NHS Trust said plans will be discussed at a meeting on Thursday.
Plans could also see services for women and children moved to Lincoln.
If accident and emergency departments at Boston and Grantham close to patients after 2300 BST, Lincoln County Hospital would be the only centre providing these services in the area during the night.
Managers need to reduce debts of £17.5m and stem the current overspend of almost £2.5m a month.
More than 7,000 people work for the trust and unions fear 1,000 jobs could go when final plans are announced.