West Midlands Ambulance Service is dealing with a huge increase in 999 calls and recorded its fourth busiest day on record on Tuesday, taking nearly 6,400 calls.
The Express & Star and Shropshire Star have been told that by 6.30pm the backlog was above 500 calls, with operators left struggling to get ambulances out to patients.
Ambulance chiefs have apologised to patients and insisted staff and volunteers were "working tirelessly" to reach patients as quickly as possible.
The situation has deteriorated in recent months due to a spike in demand since the Covid pandemic started to subside.
It is understood that other factors contributing to delays include the public's lack of access to GPs, staff absences and an increase in 'repeat' 999 calls - where patients contact emergency services while they are waiting for an ambulance.
Meanwhile lengthy handover delays due to hospital pressures have seen crews often left 'babysitting' patients in ambulances stuck outside the region's A&E departments.
It came after Boris Johnson announced a tax rise to raise billions to help clear the pandemic treatment backlog that is crippling the NHS.
A WMAS spokesperson said: "As a service we’re experiencing another surge in demand this week.
"Monday and Tuesday were in the top 10 busiest days on record for the service. Monday saw the service take 5,577 calls whilst Tuesday saw the fourth busiest day ever with the service receiving 6,392 calls.
"This is far busier than any New Year’s Eve, traditionally the busiest day of the year.
"It is taking longer than we would want to get to many patients for which we apologise. Despite this, our staff and volunteers are working tirelessly across the West Midlands to reach patients as quickly as possible."
WMAS said the rise in demand was made worse by 'repeat' calls, where people who have already booked an ambulance call back to check where it is.
This applied to around four in 10 calls earlier this week, the service said.
The spokesperson added: “If you have called 999 and an ambulance has been arranged for you, please do not call back asking for a time of arrival as this could delay us speaking to another patient who needs our help.
"Only call back if the patient’s condition worsens or you no longer need our help."
WMAS started seeing record demand levels in June. Since then it has regularly received more than 6,000 calls a day - around 2,000 more than would normally be expected.
WMAS said 19 of its 20 busiest days ever have come since June this year. The number of calls received has gone past 6,000 a day on several occasions. On a 'normal' day the service would get around 2,000 calls.