Despite its healthy financial position, NHS Wandsworth is being asked to make millions of pounds of savings to help plug the gap in the healthcare budget across south-west London.

After achieving a budget surplus of £12m in 2010/11, the PCT is being asked to make savings as NHS South West London - a temporary organisation that has joined the management teams of five primary care trusts, including NHS Wandsworth - is aiming to close a financial gap with a huge savings programme of £64.5m in 2011/12.

There are also concerns that Wandsworth's surplus could be used to help out other boroughs in financial difficulties in the future.

Steve Davies, interim director of its Quality, Innovation, Productivity and Prevention programme, said the trusts had "nothing to fall back on." He added: "Clearly the challenge is enormous - no-one is denying that." In 2014 the trusts, which currently buy care for patients, will be replaced with GP-lead groups as part of Government health reforms.

NHS Wandsworth has been tasked with producing a £7m savings plan to make a £12.3m budget surplus for this financial year.

These will include £1.65m cuts from mental health and learning disability services and £2.3m from primary care.

It will also have to make spending reductions of £862,000 to planned care and cut medicine costs of £650,000.

Total planned savings across the region include £10.5m from back office functions and £7.5m from mental health and learning disability services to deliver s £32m surplus for the year.

An NHS South West London spokesman said savings would be achieved through leaner management, making sure people are treated in the right settings and working to keep people healthy and prevent the need for expensive care.

But chief executive Ann Radmore warned NHS London - which oversees healthcare in the capital - did not think the new trust's targets were as "stretching" as those demanded elsewhere in the city.