Newly appointed health secretary Andy Burnham has admitted that it would be "ridiculous" to promise growth for the NHS after 2011.
Mr Burnham, in the middle of a row with the Tories over a possible £15bn funding shortfall over the next decade, said it would be impossible to make guarantees on the future.
He told the NHS Confederation annual conference in Liverpool: "People might not believe everything we say these days but there's confidence and a wider recognition we have looked after the NHS and made it our priority."
Mr Burnham explained his vision for the NHS to confederation members – who represent 95% of all NHS organisations.
In his 30-minute speech he described NHS managers as the "backbone of British public service".
He praised delegates for cutting waiting times and improving performance but insisted that bosses push on during financially tough times.
He said: "It is not time for the shutters to be put up and the protection of budgets."
Mr Burnham also announced that the country's best performing primary care trusts would be rewarded with more freedom, explaining it was time to "deep-clean the regime" over targets.
He also revealed that PCTs which have improved on preventing expensive problems such as obesity and smoking will be given "more flexibility and control over how they operate" from 2010/11.