The admission comes after the Scottish Government put in a request for military assistance as the ambulance service comes under increasing strain.
Glasgow-based paramedic Liam Boylan, who has worked in the service for 28 years, said the situation was “as bad as I’ve ever seen it”.
He has faced waits of up to three-and-a-half hours outside the A&E department for patients to be offloaded.
Another ambulance worker based in a rural area, who did not wish to be named, said on every recent trip to a hospital he has been forced to wait more than three hours.
“I’m dealing with a lot of Covid, unvaccinated people who tend to be in a bad way,” he said.
“The majority of queuing I’ve seen is for Covid patients or people with breathing difficulties that could be potential Covid.
“And that wait could be hours. I’ve never had a shorter wait than three hours.”
He also said the situation is worse than anything he’s seen in five years.
“It’s not anything except that hospitals can’t cope with demand,” he said.
"Among ambulance staff everybody’s demoralised at the moment as we hear that ambulances can’t cope with demand.
“But ambulances can cope with demand, it’s the hospitals which can’t take the patients.”
Mr Boylan called for “common sense” from people in calling an ambulance, and praised the health secretary’s advice to “think twice” before doing so.
“What we’re seeing is people phoning up with Covid symptoms, and being unwell, but not so unwell that they can’t just get advice from the NHS website,” he said.
“The default position seems to be to phone an ambulance and that includes people with stomach aches and the like.”
He added: “It’s not as if we’ve got a huge amount of resources and we’re just not bothering going, we’re trying to get to the people who need us the most.
“But in between that, we’re sweeping up everything – we’re sweeping up mental health and people drunk at events like TRNSMT over the weekend.
“We seem to be the cloth that will mop everything up.”
David O’Connor, UNISON ambulance officer, said the union was concerned about ambulance staff working through breaks and reaching unsafe levels of tiredness.
“A major issue for us is trying to achieve rest breaks,” he said.
“We are seeing more people calling in with fatigue after working for eight hours of a ten or 12-hour shift and still haven’t received a break.
“They’re calling in and saying they can’t go on any more, they can’t function properly and safely, treat patients, or drive an ambulance safely.
“We’re seeing that quite a lot just now.”
Mr O’Connor added: “This is not solely an ambulance problem. This goes into every single health board, where ambulances are waiting outside A&E for hours to offload their patients.
“If they weren’t waiting there, they would be out answering calls a lot quicker than they are able to do just now.
“The issue with NHS boards is they don’t have enough beds, because they can’t get people out of hospital into health and social care settings, because they don’t have staff.”