Mr Prentis, an architect of the pre-election truce between the unions and Tony Blair and Gordon Brown, accused them of using the "dark politics of fear" to get re-elected.
Commenting on the government's branding of young people as "hoodies", he said: "I tell you who the real hoodies are -the faceless multinational companies making a killing from our public services; faceless political advisers brought in from big business, private companies, the CBI, to reform public services."
He singled out Andrew Adonis, the former head of the Downing Street policy unit, recently ennobled and given a junior education minister's job, and Patricia Hewitt, the health secretary, accusing them of promoting privatisation.
He went on: "Pity we can't pull down the hoods on some of these characters breaking and entering the heart of government, destroying our public service ethos ... let's serve a few Asbos on them."
He said the union's campaign against PFI projects would intensify.
There would also be a backlash from union members - who voted for strike action before the election - if the government raised the normal pension age for the public sector and Whitehall from 60 to 65. Mr Prentis accused politicians of hypocrisy for voting themselves "the best pensions in Europe".
His remarks follow a similar warning from Mark Serwotka, the general secretary of the Public and Commercial Services Union, earlier this month.
