The family of a Cheltenham grandmother who suffered a stroke say she was left waiting almost six hours for an ambulance - and three hours to enter a hospital.
The delays meant Margaret Root missed a crucial window for medical treatment to be given.
The 82-year-old is now recovering at Gloucestershire Royal Hospital but her family have lodged formal complaints with both the hospital and South Western Ambulance Service.
The hospital and ambulance service have since issued apologies.
Granddaughter Christina Smith-White described the delays as unacceptable.
In a letter to Cheltenham MP Alex Chalk, she said: “I have been left feeling angrier and more frustrated than ever.
“People should also be aware that the situation as it stands means people who are in life-threatening situations, such as having a stroke, should prepare for the worst because they certainly aren’t guaranteed help within the time frame needed.”
Christina said she was reduced to tears as a paramedic told her they had missed the three-hour window to administer the medication and treatment needed to successfully reverse any stroke damage.
The family claim patients in police custody were seen straight away, though the hospital said patients were prioritised based on need.
Fortunately, Mrs Root’s stroke was relatively mild - and she has since regained some movement in her left arm and left leg.
Christina stressed she was grateful to the paramedics and staff at the hospital, who were very apologetic and extremely helpful.
The hospital's chief executive Deborah Lee said: “We are very sorry to hear about Christina Smith-White’s concerns relating to the recent experience of her grandmother.
"We apologise for the distress caused to both Christina and her grandmother and fully acknowledge the anxiety caused to the patient and their family when waiting for emergency care.
“A combination of high demand, availability of beds, the complexity of patients presenting and the continuation of robust infection control measures in response to Covid-19 mean that our teams are working under considerable pressure and may not at times be able to admit patients to the department as quickly as they would like.
“While it may appear that the patients being escorted by the police were ‘skipping the queue’ on this occasion, it is highly unlikely that this was for care or treatment unless the illness or injury was life-threatening as patients are treated solely on the basis of their clinical priority.
"Patients under police escort are taken to a secure area to wait for clinical assessment which may have contributed to the view that they had been treated ahead of others.
MP Alex Chalk said: “I have spoken to Ms Smith-White about this very distressing case.
"When the investigations have concluded, I am going to raise any findings with the trust management so that lessons can be learned.”
Chief Executive for the ambulance service Will Warrender said: “We sincerely apologise for the trauma and upset that Christina Smith-White and her grandmother have experienced while waiting for a 999 response.
"The response to Margaret Root falls below our expected high standards and we are very sorry for the distress and anxiety that this has caused."
He said the service has been under "significant and sustained" pressure which means some patients are experiencing very long waits.
“We have a number of plans in place to improve our response times," he added.
"However, our service is at times extremely busy with people calling 999 and is also directly affected by the time it takes us to handover patients into busy hospital emergency departments, which is longer than we have ever seen before. These challenges are not isolated to the South West and are unfortunately a national problem.
“It remains an absolute priority for us and our NHS partners to reduce these delays, so we can be there for our patients, while prioritising those who are most seriously injured and ill."