In a reference to the Prime Minister's speech on Tuesday, Rodney Bickerstaffe, general secretary of the public service union Unison, Britain's largest, urged the government to enter "the real world" over public expenditure.
The normally circumspect Mr Bickerstaffe urged ministers to abandon the dogma inherited from the Conservatives.
He accused the Treasury of espousing a "contorted and distorted" perspective that capital investment in the public infrastructure was not investment, but debt.
"It is not seen that way anywhere else and the government should try and come into line with the real world," he said.
The Public Finance Initiative (PFI), under review by the government, was also part of the dogma which argued that "if it's public it's always, always bad and if it's private it's always, always good". Delegates argued that the PFI, where business funds projects and then runs them for up for 60 years was simply a back door to privatisation.
The Unison leader called for the government to abandon the expenditure limits inherited from the Conservatives.
Referring to Tony Blair's plea for modernisation, Mr Bickerstaffe said it could not be the modern way to have patients on trolleys, children without nutritious school meals and the elderly worrying about the future of public services
Mary Turner, president of the GMB general union and a dinner lady, said that while her members were flexible as the Prime Minister suggested, they were not keen on remaining so.
Bob Crow, assistant general secretary of the RMT rail union, said he and his members worked in the real world where there had been thousands of job losses and where fat cats were lining their back pockets.
Congress unanimously passed a resolution calling for greater public investment and the abandonment of the PFI.Reuse content