Government reforms will increase financial problems in the NHS unless more effective measures to deal with deficits are introduced, a study says.
The NHS in England could be heading for a £620m deficit
The King's Fund predicted one in five trusts will develop huge deficits as the NHS becomes more market driven through measures like patient choice.
Last week it was announced the NHS in England could face a deficit of £620m.
Health Secretary Patricia Hewitt said it was acceptable to delay surgery to save money if waiting targets were met.
Patients needing for non-emergency surgery should be waiting no longer than six months.
She said while it would be worrying for patients, it was better than "having to cut back on community and district nurses".
But Shadow Health Secretary Andrew Lansley said ministers were now putting pressure on doctors and nurses to go against their clinical judgement.
And Liberal Democrat health spokesman Steve Webb added such moves would leave patients waiting for operations in "despair".
Meanwhile, NHS chief executive Sir Nigel Crisp's annual report has praised the progress made on reducing hospital waiting lists and disease death rates.
However, Ms Hewitt has said she will take tough action against trusts which cannot sort out their finances.
She has ordered hit squads of consultants to go into the worst performing trusts to help reduce the debts. Two thirds of the predicted deficits are concentrated in 37 trusts.
And she said if NHS managers could be removed if needed.
"Where there is a management failure, we will put in new, stronger management to get a grip of the problem."
Addressing the Health Select Committee on Tuesday, Ms Hewitt said she doubted the end of year deficit would be as high as £620m, claiming the plan was to reduce it to £200m by March and to balance a year later.
It comes as the Healthcare Commission announced tougher measures to assess financial performance amid the rising level of deficits the NHS is facing.
The NHS watchdog said its new ratings system will tighten the requirements needed to gain a top grade, taking more account of a trust's finances.
But the King's Fund report has called for much more wide-ranging reform.
The think-tank said that as reforms such as patient choice, greater use of community services, increased private sector provision and a new system of payment kick in, different parts of the NHS will be pitted against one another.
It predicted some trusts would fail to attract enough funding and run up "large and significant" deficits.
Report author Dr Keith Palmer said: "Parts of the NHS are already experiencing large deficits despite unprecedented increases in funding and we expect deficits will increase at some NHS trusts when the reforms begin to bite in earnest."
The think-tank urged the government to act by overhauling the system in place for dealing with trusts which develop financial problems.
It said the present system was failing to properly diagnose the problem and was leading to the government bailing out trusts.
Instead, it wants trusts to be given help to draw up restructuring plans when deficits reach a certain point.
Those which failed to turn themselves around should potentially face closure or being taken over by another trust or private firm, the think-tank added.
Nigel Edwards, policy director of the NHS Confederation, said many of the measures recommended were common sense that would lead to local services "becoming financially sustainable".