Unrelenting pressure on two Sussex hospitals forced health bosses to declare a “major incident” for the first time in more than five years.

Non-urgent operations were cancelled and patients were turned away as already overstretched staff at the Royal Sussex County Hospital, Brighton, and the Princess Royal Hospital, Haywards Heath, were told to focus solely on freeing beds until the hospitals “got their heads back above water”.

Meetings and study leave were cancelled to deal with the crisis until the major incident was lifted on Friday afternoon.

In recent weeks, the Brighton and Sussex University Hospitals Trust, which runs both sites, has been forced to call in experts from the Department of Health to help it deal with spiralling waiting times in accident and emergency departments. The struggle to provide enough beds has seen 1,300 A&E patients wait up to 12 hours for a bed in the past five months - with 25 people waiting more than 12 hours.

After an “extremely difficult” weekend at the hospital, South East Coast Ambulance Service then dealt with a quarter more people in Brighton than predicted on Tuesday, putting further strain on services.

By Wednesday morning all of the hospitals' wards and emergency departments were full and an “internal major incident” was called.

Two wards were also closed to admissions this week after being infected with Norovirus.

Ambulance crews were asked to “robustly assess” people before taking them to hospital.

Nearly 200 patients were sent home in 48 hours - a third more than would usually be discharged - in order to ease the pressure.

Chief executive of Brighton and Sussex University Hospitals Chris Adcock told staff in his weekly newsletter: “By Wednesday morning, with the pressure at a peak, we had no option but to call an internal major incident.

“It is a status which allows us to focus the entire effort of the hospital, and those around us, and to take a series of short-term actions to relieve the tide of unrelenting pressure across the hospital for long enough to get our heads back above water.

“Declaring an internal major incident was not a decision we took lightly. “But it was a proactive and informed decision based on a collective recognition that we needed to do something fundamentally different, and it was the right thing to do, because it worked.”

He said he was “blown away” by the “positive and constructive” reaction from clinical and managerial staff.

Tom Scanlon, director of public health for Brighton and Hove City Council, said: “It's a worrying time but people need to realise this is not the norm.

“January and February we see a lot of people come in with respiratory, cardio and trauma injuries from falls.

“Alcohol is also a constant strain.”

The hospital said colder weather as well as people going to hospital instead of calling out-of-hours doctor or booking an appointment with a GP was partly to blame for the problems.