Hundreds of patients are being taken to hospital by police because ambulances fail to arrive in time, new figures reveal.
Scotland Yard disclosed that it was forced to transport people to hospital on 903 occasions last year.
The figures, released by the Metropolitan Police following a Freedom of Information request, mean officers were sent to stand in for paramedics at a rate of more than twice a day in 2014.
The force - Britain's largest - was asked how many times officers were required to take someone to hospital because ambulances have not turned up in time.
July was the busiest month, when police transported patients on 102 occasions.
The trend continued this year, with figures showing there were 28 such incidents in the first half of January.
In recent months senior police have raised concerns about officers attending incidents that should be dealt with by paramedics.
Simon Cole, Chief Constable of Leicestershire Police, told the Sunday Telegraph in November: "I am concerned that police officers on occasion are having to transport people to hospital when they should not have to do so, because there isn't ambulance availability.
"It is not uncommon, and we are working hard to understand what contributes to it. We are anxious that we are spending time supporting the ambulance service."
Steve White, chairman of the Police Federation of England and Wales, said: "Police officers routinely find themselves dealing with medical emergencies, with patrol cars forced to become makeshift ambulances.
"Many of our officers are being called to incidents where emergency medical care is needed but are left waiting for long periods of time for paramedics to arrive, often only to be told that there are none available.
"They then have no choice but to convey the casualties to hospital themselves. The issue can be particularly prevalent at peak times, such as in busy town and city centres during weekends - a time when all emergency services commonly find themselves stretched to capacity.
"While we understand and appreciate only too well the strain that the Government's public service reforms have placed on all emergency services, any time spent by police transporting casualties to hospital is time they are not spending on the streets.
"It is that very duty of care to the public that results in officers taking casualties to hospital when they are left with no other option."