The Welsh Ambulance Service has declared a “critical incident” because of significantly increased demand across the 999 service and extensive handover delays.

The service, which covers three million-plus people across Wales, said more than 340 calls were waiting to be answered at the time the critical incident was declared on Monday evening.

More than half of the Trust’s ambulances were also waiting to hand over patients outside hospitals, leading to some people waiting “many hours” for an ambulance and staff taking longer to answer calls.

It is very rare that we declare a critical incident, but with significant demand on our service and more than 90 ambulances waiting to hand over patients outside of hospital, our ability to help patients has been impacted

The service has urged the public to call 999 only for serious emergencies.

The Trust said it has taken additional measures to ensure it can continue to deliver a service to the public.

Stephen Sheldon, head of service, said: “It is very rare that we declare a critical incident, but with significant demand on our service and more than 90 ambulances waiting to hand over patients outside of hospital, our ability to help patients has been impacted.

“Regrettably, this means that some patients will wait longer for an ambulance to arrive and for their calls to be answered.

“For that, we are very sorry because this is not the level of service we want to provide.

“We understand that this is frustrating for patients, but can assure them that we are doing everything we can to relieve the pressure on our service.

“The public can help by only calling 999 in the event of a life-threatening emergency – that’s a cardiac arrest, chest pain or breathing difficulties, loss of consciousness, choking or catastrophic bleeding.

“If it’s not a life-threatening emergency, then it’s important you use one of the many alternatives to 999, starting with the symptom checkers on our NHS 111 Wales website as well as your GP, pharmacist and minor injuries unit.

“We must protect our precious resources for those who need them the most.

“Our staff and volunteers are doing a brilliant job under difficult circumstances, and we cannot thank them enough for their hard work during these very challenging times across the health service.”