Any attempts to cut the pay of NHS staff and other public sector workers may lead to strikes, unions have warned.

They were challenging statements by chancellor Alistair Darling that future wages must be “fair” to private sector workers facing a recession-fuelled pay squeeze.

He had been responding to calls by Audit Commission boss Steve Bundred for £5bn to be cut from the wages bill to help the economy recover from the downturn.

Mr Bundred claimed that public sector workers would “tolerate” a freeze as they had “done well” over the last 10 years.

But union leaders warned that any suggestion that the government might try to impose real-terms pay cuts would spark demands for strike action.

Mr Darling had told Sky News’ Sunday Live that public sector pay “obviously must reflect prevailing conditions, particular in view of the fact that inflation is falling”.

He was backed by shadow business secretary Kenneth Clarke, who said: “Public sector pay certainly has to reflect what is going on in the private sector to some extent, and it has also got to reflect the current low level of inflation.”

He criticised the “absurd explosion” in public sector pay in previous years.