A woman died from a brain haemorrhage after at least three hospitals refused to admit her for surgery because they had no intensive care beds.
A coroner ruled that 57-year-old Mary Muldowney would probably have survived if she had been given immediate life-saving surgery to stem the bleeding.
Ms Muldowney was admitted to East Surrey Hospital in Redhill on July 20 last year where doctors immediately suspected a bleed on the brain.
A CT scan carried out just over an hour later showed heavy bleeds and doctors requested an immediate transfer to a specialist neurosurgical unit for surgery.
But three units - St George's Hospital in Tooting, south-west London, the Royal Sussex County Hospital in Brighton, and King's College Hospital in London - refused the request due to having no beds.
Other hospitals also said they did not have an available intensive care bed.
In a letter to bosses at NHS England, inner north London coroner Mary Hassell said: "In desperation, knowing of the neurosurgical expertise of a former colleague, one of the East Surrey Hospital doctors went out of area and rang a consultant neurosurgeon at the Royal London Hospital (RLH).
"Invoking the universal acceptance policy, he accepted transfer immediately, though in fact the RLH had no intensive care bed available at that time.
"Meanwhile, at about 1pm, Ms Muldowney woke up very briefly while intubated and interacted with her daughter.
"Ms Muldowney was transferred to the RLH and taken straight to theatre at 4.40pm. Unfortunately, her pupils had become fixed and dilated in the ambulance during transfer to the RLH and surgery did not save her.
"If she had been transferred promptly, it probably would have."
The coroner, who recorded a narrative verdict, said evidence showed that Ms Muldowney "could have been transferred, undergone surgery, spent time in recovery, and then an intensive care bed procured".
"If such a bed was still unavailable, she could then have been transferred to a different hospital, at least having undergone the time critical clot evacuation and aneurysm clipping.
"With prompt transfer and surgery, Ms Muldowney would probably have survived.
"In my opinion, action should be taken to prevent future deaths and I believe that you have the power to take such action."
NHS England medical director Sir Bruce Keogh said he was "very sorry" to read of the circumstances around Ms Muldowney's death and that a serious patient safety issue had been raised.
He said Professor Simon Mackenzie, from St George's Hospital, had suggested Ms Muldowney "was not deemed by the neurosurgical services to which she was being referred to require immediate life-saving surgery" and fell outside the scope of the universal acceptance policy.
Prof Mackenzie said he believed St George's provided acceptable care because Ms Muldowney suffered a re-bleed during the ambulance transfer to the RLH.
Prof Mackenzie said that "although at the time of the referral to the St George's neurosurgical unit a re-bleed was a possibility, this was not the reason for her urgent transfer", Sir Bruce wrote.
But he said the process of securing a bed added a delay of just less than two hours to the acceptance process.
Sir Bruce said there was a clear "difference in perspective" between doctors at East Surrey Hospital and St George's, and a meeting is to be held between clinicians at the two units.
He said the findings would be fed into broader work around the way patients are referred between hospitals.
The coroner's report and letter from Sir Bruce were first reported by the Health Service Journal.
The findings come after a winter where hospitals have issued dozens of serious alerts over a lack of beds. BBC documentary Hospital has highlighted how patients are turned away or have operations cancelled due to a lack of beds, including intensive care beds.