FINANCIAL mismanagement at NHS Croydon is a key cause of its successor's £20 million deficit, two senior health officials have claimed.
The primary care trust (PCT) posted a £5.5 million surplus in 2010/11 when it had in fact overspent by £28 million.
NHS London has stood by the findings of a report it commissioned into the scandal which said there had been no adverse impact on healthcare.
Paula Swann, chief officer of Croydon Clinical Commissioning Group, which replaced the PCT in April, said the new organisation has been left with a legacy of overspending.
"NHS Croydon left us with an underlying deficit," she said.
"At that point of time they were spending a lot more money than they had resources for.
"The issue is the local health economy weren't aware of that so they didn't take appropriate action quick enough to enable additional savings to take place.
"It has made planning a way out of our current situation much more difficult."
Croydon CCG did not have to directly repay any of its predecessor's £23 million overspend because it was settled using money from elsewhere in the NHS, using what is called a prior period adjustment.
"The problem in 2010/11 was fixed, but the money wasn't spent on services just for that period, but over a number of years," said Mike Sexton, chief financial officer at Croydon CCG.
"Say we spent £10 million on A&E and we only had a budget for £9 million. That's a £1 million deficit. Then imagine we sorted that out with a prior period adjustment.
"Next year we know there will be £10 million of people using the A&E, but we only have £9 million, and the population has grown.
"The reality is it takes time to bridge that gap.
"We're left with a legacy of demand and behaviour which has forced us to look at efficiencies across all areas."
The CCG must save £47 million if it is to break even – an annual statutory duty – by 2015. It has predicted a £19.9 million deficit this year, not including making £14 million of savings.
On Tuesday Health Secretary Jeremy Hunt told the Commons he is "extremely concerned" at the lack of accountability at NHS Croydon.
It wrote to Mr Hunt and called on him to intervene. Responding to a question from Croydon Central Gavin Barwell, the Secretary of State said: "Accountability is extremely important and local authorities can require members or employees of local health service commissioners to appear and answer questions. NHS organisations and individuals should co-operate with that."
