Video report by Chris Kiddey
A man from West Yorkshire who was having a heart attack says he was told to "have a glass of water and get himself to hospital" by a 999 call handler.
Mark Burden, 52, fell ill at his home in Baildon in December and says the advice given when his partner's son rang for an ambulance was life-threatening.
He said the call handler told him: "At the moment we are very busy. I suggest you give him a glass of water and tell him to make his own way to the hospital."
Mr Burden said he was fortunate his wife was able to take him to Bradford Royal Infirmary 15 minutes after the call.
He had suffered from a rare spontaneous coronary artery dissection (SCAD), and had to be transferred from the BRI to Leeds General Infirmary to have a stent – a tube designed to keep an artery open – put in.
The Yorkshire Ambulance Service has apologised and said it has been experiencing serious pressure on its services.
Mr Burden said: "When you are having a suspected heart attack you should be dealt with straight away and get the attention and ambulance you need straight away.
"I have been let down badly. It could have cost me my life."
A spokesperson from the Yorkshire Ambulance Service said its patient relations team had been in contact with Mr Burden.
They added: "Like all other ambulance services across the country, we have been experiencing significant operational pressures for some time and, whilst our dedicated staff are doing their best to respond as quickly as possible to all emergencies, we acknowledge that some patients are having to wait longer for an ambulance response."
The British Heart Foundation said, despite Mr Burden's case, people should still dial 999 in a medical emergency.
In a statement, they said: "We also appreciate that the NHS and all allied services are under unprecedented pressure but we would continue to say call 999, use that as your first response and get that medical attention as quickly as you can."
Mark Burden is continuing his recovery - and has said he hopes to be back at work next week.