London's air ambulance is bidding to launch a 24-hour service that will save hundreds of lives a year - but it needs £500,000 annually to pay for the plan.

The bright red helicopter has become a familiar sight in the capital as it swoops to treat casualties in some of the most built-up places in the city.

The Helicopter Emergency Medical Service treats 1,500 cases a year. It can take doctors and paramedics anywhere within the M25 within 12 minutes - but because of safety issues with landing it cannot operate in the dark, when many serious accidents take place.

In these cases it sends out rapid response cars - but due to a lack of funding they do not run between 1am and 7.30am on weekdays and 6.45pm and 8.30am at weekends.

Almost one third of calls received by Hems so far this year could not be answered by it because they came in the early hours.

Bosses of the service, based at the Royal London Hospital in Whitechapel, want to raise the cash by the end of the year.

It would means hundreds of people who are attacked or suffer accidents at night would have a better chance of survival.

The air ambulance played a crucial role after the 7 July terror attacks and has attended all the major incidents of the past 10 years.

But figures obtained by the Evening Standard show how little support it gets. The charity which funds the London air ambulance gets less than 7p a year on average from each city resident. People in the rest of England and Wales give more than £1 a year each to their regional air ambulance.

Campaigners said the figures put the city to shame, while others say Britain's air ambulances should not have to rely on charity.

Lead air ambulance clinician Dr Anne Weaver said: "Most people don't seem to know we have to raise our own cash. We want to be able to help people throughout the night but haven't got the funds.

"It is distressing to come to work in the morning and hear about some dreadful accident where we could have saved someone's life."

She said the appeal was even more urgent because London was under threat from terror attacks.

The capital has a major incident plan, but Dr Weaver wants to make sure the helicopter team can react in seconds. Ordinary paramedics are already available around the clock and 16 volunteer trauma doctors are on call. But medics say the helicopter team are so experienced they should be available at all times. London's air ambulance employs six doctors who specialise in major trauma plus six senior paramedics from the London Ambulance Service. There are also four pilots and four firefighters who look after the helipad at The Royal London.

The charity is part-funded by the NHS and Sir Richard Branson gives £192,000. The health service pays the wages of the doctors and paramedics. But the charity still has to find £650,000 each year from the public to stay airborne. Donations pay for the helicopter pilots, helipad firemen and the aircraft and its running costs.

London politicians said it was "a disgrace" that the city had a "part-time" air ambulance service.

Geoff Pope, Liberal Democrat health spokesman on the London Assembly, said: "People don't just experience serious emergencies during daylight. The Government must make sure sufficient funds are available." Mike Penning, Tory health spokesman for London, said: "The Government is burying its head in the sand. But I do not believe that is an excuse for Londoners not to donate. I passionately call on people to give."

After the Yorkshire air ambulance rescued Top Gear presenter Richard Hammond following a crash last year, it received at least £130,000 from the public.

A spokesman for London Ambulance Service said its paramedics could call on expert help during the night even when the air ambulance was not operating: "Paramedics and emergency medical technicians are trained for a full range of emergencies and are experienced in dealing with trauma."

26 missions to treat 7/7 victims

Within minutes the alarm sounded again, with reports of a "power surge" on the Underground. In fact, it was terrorist attacks.

By chance, there were 16 doctors and 10 paramedics attending a meeting at the Royal London Hospital helipad.

Within seconds of the call, medics abandoned the meeting and swung into action.

At 9.24am, the Helicopter Emergency Medical Service activated its major incident plan. Medical director Dr Gareth Davies began organising the dispatch of 32 trauma doctors and paramedics to the four bomb sites at Aldgate, King's Cross, Edgware Road and Tavistock Square. The helicopter flew 26 missions, taking teams around the city and transporting fresh drugs to hospitals.

While Dr Davies was one of the first medics at Aldgate, Dr Anne Weaver took over organisational duties on the helipad before she was flown to King's Cross to help.

Dr Davies, who also treated patients at King's Cross, said: "My most vivid memory is going into the Tube at Aldgate and walking along the track. "Our task was to get people out as quickly as possible so we could treat them safely above ground. "It was the worst case scenario for a major incident - in the Tube, multiple locations. "Bombs create a unique set of injuries that are very distressing, even to experienced trauma doctors and paramedics."

How you can support London's airborne heroes

It means our Helicopter Emergency Medical Service could run 24 hours a day using rapid response cars in the early hours. The charity is asking people to take part in fundraising events, get sponsored to run a race, buy a ticket for the Hems lottery, pass round a collecting tin at events or simply make a donation.

Donate by visiting www.londonsairambulance.com and press the "donate now" button. Or sign up for the lottery by downloading a form from the website or calling 020 7943 1302.

Alternatively send a cheque to "London's Air Ambulance Ltd", The Helipad, The Royal London Hospital, London E1 1BB.

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