Critically ill patients facing life-threatening emergencies are waiting longer and longer for ambulances to arrive as the service reaches a modern-day crisis point.

More than half of 999 calls to the London Ambulance Service (LAS) now see paramedics arrive outside the eight minute target set by the government, with Haringey and Barnet the worst affected of all boroughs.

It comes as the last eight months has seen response times rapidly deteriorate across the capital.

In March, all London boroughs reached or exceeded targets requiring that at least 75 per cent of immediately life-threatening calls were reached by ambulances within eight minutes.

This covers patients suffering the most serious emergencies, including those without a pulse, suffering a stroke or who have stopped breathing.

By June, every London borough had missed the target and the last set of data to be published, covering October and September, saw targets plunge to record lows.

Between March and October, the figures for Camden show a decrease from 87 per cent to 66 per cent, for Haringey from 76 per cent to 48 per cent, and for Barnet from 76 per cent to 48 per cent.

The waiting time crisis has led to accusations the service had become underfunded, overworked, short of staff, and clogged up by other failing sectors of the NHS.

Malcolm Alexander, chairman of the LAS Patients’ Forum, told the Ham&High: “Our group has been around for 10 years and I’ve never seen it get this bad – it’s catastrophic.

“Normally a level of 65 per cent would be seen as a complete disaster but we’re way beyond that.

“I believe there are a combination of reasons for the crisis.

“The pressure on paramedics in London has become so severe that many are leaving, at a rate of about eight a week. They don’t feel valued, feel they have poor leadership and are under a lot of stress.

“On top of that, you have the LAS unable to recruit new people.

“And finally, you have a shortage of resources in other parts of the NHS causing problems.

“People are unnecessarily calling ambulances because they can’t get an appointment with their GP, while rising handover times at hospitals mean ambulances are having to wait in queues outside A&Es rather than rush to the next emergency.”

Joanne McCartney, Labour London Assembly Member for Enfield and Haringey, blamed funding for the crisis.

She said: “Whilst the ambulance service is doing its utmost to keep Londoners safe the increased demand and cuts to their budget have left them fatally overstretched.

“People facing life threatening emergencies in Haringey are now waiting longer than they should for an ambulance more than 50 per cent of the time.

“With LAS response times in free fall the government has to accept the scale of the crisis and step in to ensure the service can cope.”

But a spokesman denied the LAS had received a significant budget cut, saying its funding had “actually increased”.

Paul Gates, deputy director of operations at LAS for North Central London, said: “Every year demand on our service increases and we are now responding to nearly 8 per cent more patients in a serious and life-threatening condition than last year.

“There is also a shortage of paramedics in the UK, which is making it difficult to recruit, but we’ve launched a national and international recruitment campaign to bring in hundreds more frontline staff across London.”