Yorkshire Ambulance Service has insisted it provides a safe service after it emerged that the longest a patient waited was 23 hours and 59 minutes.
It was the fifth longest wait recorded by the UK’s ambulance trusts between June 2017 and 2018, according to figures obtained by the BBC.
Stephen Segasby, Deputy Director of Operations at Yorkshire Ambulance Service, said checks were carried out on patients’ welfare if ambulances were delayed.
He said: “Our main priority is to respond to patients in a serious or life-threatening condition as quickly as possible.
“Overall demand for emergency ambulances is increasing year-on-year and this pressure is reflected in all NHS services across the whole country.
Welsh Ambulance Service recorded the longest delays, taking more than 50 hours to respond to 999 calls on four occasions over the course of a year.
One patient waited for 62 hours.
Meanwhile, the East of England, South East Coast and South Central ambulance services all recorded longest waits of more than 24 hours between June 2017 and 2018, the BBC said.
The trusts said the longest waits were for less serious calls, and that they had to prioritise people in life-threatening or urgent conditions.
The Welsh Ambulance Service said it accepted that some patients waited “far longer than anyone would like”, but said the figures were “not typical”.