An NHS source said staff at the QEUH were forced to stop admitting emergency cases and claimed paramedics were waiting more than eight hours to hand over sick patients.

NHS Ayrshire and Arran said today that "due to current pressures" ambulances were also being diverted from University Hospital Crosshouse to University Hospital Ayr for a short period of time "in the interests of patient safety".

It comes as new figures showed an estimated one in 20 people were infected with Covid in the week to December 31 - the highest prevalence at any point in the pandemic, and up from one in 40 the previous week.

The number of patients in hospital with the coronavirus has almost doubled since Christmas.

There were 527 patients with the virus in Scottish hospitals on December 25, a figure that now stands at 1,223. The total requiring intensive care has risen to 42 but well below the third-wave peak of 100.

A spokeswoman for the Scottish Ambulance Service said the longest turnaround time at the QEUH was 5hrs 37 mins and said transfer delays was leading to lengthier waiting times for patients dialling 999.

READ MORE: More than 16,000 new Covid cases recorded and five deaths  

During busy periods, before the pandemic, patients in need of a bed would lie on trolleys in the corridors around emergency departments until space became available. However this practice now risks exposing patients to Covid-19.

A spokesman for NHS Greater Glasgow and Clyde said: "In recent weeks pressures on services have continued due to Covid infections, rising A&E attendances, and staffing pressures.

"Within NHSGGC all our sites are operating well above normal capacity which is having a significant impact on service provision.

"We want to apologise to anyone who has had a lengthy wait for emergency care.

"Our network of hospitals work together to respond to demand and this includes diverting patients before they arrive at a particular site when it is facing high demand.

"All our emergency sites remain open and continue to admit emergency patients.

"We would urge everyone that, unless their condition is life-threatening, they should not attend an Emergency Department."

A Scottish Ambulance Service spokeswoman added: "NHS services have been experiencing significant pressure over the last week, exacerbated by the ongoing Omicron variant.

"These pressures are causing longer hospital turnaround times due to emergency departments being at near or full capacity and this in turn is impacting upon our ability to get crews back out on the road to help patients, leading to lengthier response times. 

 "Health Boards and the Scottish Ambulance Service are working together to try and mitigate wait times through joint escalation plans, and a number of other steps have been introduced to minimise ambulance waiting times, including introducing Hospital Ambulance Liaison Officers to manage flow, and increasing alternative care pathways for ambulance clinicians to support patients in the community.”