Hospital bosses could shut an accident and emergency department at night in order to combat a staffing crisis.
United Lincolnshire Hospitals NHS Trust said it is considering slashing opening hours at Grantham and District Hospital due to a severe shortage of doctors.
It said closing the Grantham A&E rather than the departments at Lincoln County Hospital or Pilgrim Hospital in Boston was the "safest option".
A spokesman for the trust said failing to act "may put patients at risk".
The Royal College for Emergency Medicine (RCEM) said news of the potential closure was "disappointing, yet unsurprising".
Dr Suneil Kapadia, medical director at the trust, said: "We haven’t made a final decision yet and we hope to avoid this, but the reality is we will need to temporarily reduce the opening hours of A&E at Grantham.
"The quality and safety of patient care is the trust’s number one priority and we haven’t rested on our laurels."
A recruitment drive both in the UK and overseas and the offer of premium rates to attract agency doctors failed to attract more staff, while