Patrick Royle was cycling 58 miles between London and Oxford during a heatwave in 2006 to raise money for a leukaemia charity.

But in "exceptionally hot" conditions, Mr Royle – son of military historian Trevor – staggered down a residential street just short of the finish line and collapsed.

A coroner has now ruled that the 31-year-old father-of-one's death was aggravated by the "neglect" of the ambulance service for a breakdown in communication which saw them take 55 minutes to reach him.

Today his parents, who live in Joppa, slammed the NHS and ambulance service for the events which contributed to Mr Royle's death.

His mother Hannah, 64, herself a retired GP, said: "The fact that there were no ambulances available at all at the time is unbelievable. The NHS is not fulfilling its duties towards patients in this country. I think the Red Cross has been very disappointing in the way they approached this event."

His father Trevor, 63, said his death was "an unnecessary waste of life".

He added: "Mistakes and lack of communication led to my son's death."

The inquest heard that by the time the ambulances reached Mr Royle he was dead.

During that time two ambulances from the British Red Cross, who were providing medical cover for the event, were parked nearby – one only 60 seconds away.

But due to a breakdown in communication with the ambulance service those crews were not alerted to Mr Royle's plight, the inquest at Oxford Coroner's Court was told.

Coroner Dr Richard Whittington recorded a verdict of misadventure aggravated by neglect to provide communication that provided a prompt ambulance response.

The court had heard how a police officer, doctor and a nurse who happened to be passing went to the aid of Mr Royle and a paramedic in a car arrived half an hour later but his condition deteriorated.

He suffered heart failure and attempts to resuscitate him were halted when the ambulance eventually arrived.

The inquest was told that Mr Royle, an accounts manager who lived in south-west London, may have survived if he had been transferred to hospital – just three-and-a-half miles away – sooner.

Mr Royle, who was known as Paddy, was taking part in the ride to raise money for a children's leukaemia charity with his brother-in-law, a work colleague and another man on July 2, 2006 during an early summer heatwave.