The worst offender, St George’s Hospital in Tooting, has been forced to pay out almost £47,000 after crews were called out unnecessarily 168 times in 12 months – more than three times a week.

London Fire Brigade (LFB) introduced the £295-a-time penalty against premises responsible for more than nine bogus alerts a year in an effort to stop wasting time and money.

The trend has been blamed on poorly-maintained automatic alarms which immediately notify 999 call handlers of any incident, from smouldering dust to burnt toast.

University College Hospital in Euston Road had 75 false alarms, Chase Farm in Enfield made 66 and University Hospital Lewisham had 62.

Critics today said the fines were simply “shuffling taxpayers’ money around” and would hit short-staffed NHS wards.

Shadow health minister Andrew Gwynne said: “The NHS can’t afford these penalties. The money is desperately needed for nurses on short-staffed wards across London.”

But the LFB insisted the measure would force managers to keep their alarms up to scratch.

Neil Orbell, head of fire safety at LFB, said: “This is not a money-making scheme and the last organisations we want to charge are hospitals.

“However, we are called to over 30,000 false alarms every year and some hospitals we go to nearly every week.”

James Cleverly, chairman of the London Fire and Emergency Planning Authority, defended the penalties as “morally and financially the right thing to do.”

He said: “This will sting a little bit but we want them to change the way they manage their alarm systems. Enough is enough, these hospitals need to up their game.”

The fire brigade said that despite a 7.3per cent drop since the introduction of the charge it was still responding to one false alarm every 15 minutes.

Fines worth close to £500,000 were issued altogether last year but so far less than half has been recovered – with £265,740 still outstanding.

A spokesman for St George’s Hospital Trust said: “False fire alarms cost money and waste time so we are currently embarking on a £4million pound, three-year programme to update all 5,500 fire sensors across the site.”

Andy Sylvester, of the Taxpayers’ Alliance, said: “It’s easy to understand the Fire Brigade’s frustration, but robbing Peter to pay Paul seems a pointless way to use taxpayers’ money.”