The total debt of NHS trusts in London is bigger than any other part of the country, a BBC survey has found.
London NHS trusts are £240.5m in debt
The deficit is £240.5m, compared to the total NHS trusts debt across the country of more than £1bn.
Hammersmith Hospitals NHS Trust had the biggest debt at £35.3m, followed by Hillingdon Primary Care Trust (£25.6m).
Both have introduced savings measures including staffing reviews which have led to recruitment freezes and possible redundancies.
Of London's 75 NHS trusts, 16 have a debt of above £5m or more, 10 of £10m or more and six of at least £15m.
North West London Hospitals NHS Trust has the third highest debt at £25.5m, Kensington and Chelsea Primary Care Trust (PCT) has a debt of £20.9m, Queen Elizabeth Hospital NHS Trust is £18.9m in deficit and University College London Hospitals NHS Trust is £17.4m in the red.
A spokesman for Hammersmith Hospitals NHS Trust said it has made savings and reviewed staffing levels which could result in redundancies.
"We have been working closely with our staff to identify how we can reduce our costs whilst treating more patients and maintaining high clinical standards.
"Over the last 18 months doctors, nurses and managers have been successful in improving efficiency by reducing length of stay, minimising inappropriate referrals, undertaking more day surgery, developing and implementing innovative care for patients, reducing dependence on locum and agency staff, better bed management, reducing hospital acquired infections and more effective prescribing.
"We also systematically review all vacancies and recruitment to ensure that our staffing reflects both new ways of working and responds to demand.
"We have so far been successful in reducing agency and locum staff spending and taking out unnecessary vacant posts.
"By March 2006 we expect the workforce to have dropped by 300 posts and aim to avoid redundancies but cannot guarantee to do so."
Hillingdon PCT introduced a recruitment freeze for several months but had to lift it when it caused a service to be clinically unsafe.
"The savings that operational service were asked to make on the whole have been made, but have been cancelled out by increased hospital costs," a Hillingdon PCT spokesman said.
"We are working closely with Hillingdon Hospital, our local hospital, on a variety of plans and measures.
"At the same time we are working with others in the health and social care economy, mainly Social Services, to ensure appropriate, timely and effective care, mainly aimed at keeping people out of hospital - but safe and well."