A mother has said her 16-year-old son waited two hours for an ambulance to take him 300 yards to intensive care.
A transcript of a phone call at the hospital has been released
Jackie Gallimore said three ambulances were outside A&E at University Hospital of North Staffordshire but none could be used to pick up Luke.
Luke, who had leukaemia, slipped into a coma as he waited to be transferred from a ward and never recovered.
His family has now released a transcript of the phone call in which Luke's doctor pleads for an ambulance.
Luke was on oxygen at the hospital and could not be moved from his bed, which was why an ambulance was needed.
His mother, from Stoke-on-Trent, said: "It's bad enough him being diagnosed as having leukaemia but the memory of my son sat waiting for that ambulance for two hours will never go away.
"No family should have to go through that."
One hour after the first call for an ambulance, Dr Keiron Lennon asks ambulance controllers why Luke had still not been moved.
He said: "This is extremely urgent. It's a 16-year-old who is critically unwell who needs to get to ICU yesterday.
A controller replied: "Doctor, A&E is holding the crews, they're not letting them clear. We've got three crews waiting in A&E to offload patients."
The doctor said: "This is absolutely critical, this lad has severe leukaemia, phenomenally septic - if he doesn't get over there very quickly he could have a cardiac arrest."
An ambulance control supervisor then came on the line and told the doctor: "It's politics and it's not fair on your patients but I'm going to speak very strongly to the bed manager. I'm sure she can get one of those cleared."
After 16 days on a ventilator, Luke died from a combination of the cancer, pneumonia and adult breathing distress syndrome.
Mrs Gallimore will meet health officials on Thursday to discuss the events leading up to the death of her son, who had just taken his GCSEs.
A Staffordshire Ambulance Service NHS Trust spokesman said: "We are supporting a complete investigation.
"However the chief executive has already written to the family very soon after the incident with the trust's sincere apologies and details of the incident that were available at that time."