The NHS has announced an overhaul of ambulance response targets, which will see fewer patients classed as life-threatening.

At present, half of all 999 calls for an ambulance are coded as the most serious, requiring a paramedic to be on the scene within eight minutes.

Under the new system, due to come into force this autumn, only around 8% of calls will be given the fastest response, which will be reduced to seven minutes on average. This will include patients not breathing or in cardiac arrest.

Around 48% - or four million calls - will be deemed an emergency, such as those having a stroke, with an average response time of 18 minutes.

The rest will be classed as urgent or non-urgent and should expect an ambulance within 120 and 180 minutes respectively.

NHS bosses said the move would save lives and that, at present, many calls classed as life-threatening turn out not to be.

It comes the day after the East of England Ambulance Service Trust (EEAST) faced accusations of sending rapid response vehicles to patients instead of ambulances in order to hit response time targets.In the current financial year to date, EEAST has reached 73.51% of the most serious incidents within eight minutes, just shy of the national target of 75%.

Professor Jonathan Benger, national clinical director for urgent care at NHS England, said the new categories were set according to patient need.

Some patients with chest pain and stroke will wait longer, but an ambulance will be sent to get them to hospital for the treatment they need, he said.

“Historically, the problem we’ve had is that a stroke patient might get a car response... then have to wait for an ambulance to take them to hospital,” he said.

The most serious calls - such as choking, drowning, asphyxiation, cases where the heart has stopped or somebody is not breathing, and complications in childbirth that could harm a child - would get a response typically within seven minutes, he said.