Video report by ITV News Medical Editor Lawrence McGinty
The Welsh ambulance service has accepted that there were delays for A&E patients at University Hospital in Cardiff last night as eyewitnesses claimed to have seen 14 ambulances queueing outside.
The service disagreed with the number, but said 999 response times had been affected.
A paramedic has told ITV News Correspondent Rupert Evelyn that waiting outside A&E departments with patients on board ambulances is becoming the norm.
He fears there could be a time when a patient deteriorates while waiting to be admitted to hospital: