A national strike involving hundreds of thousands of workers is almost certain to go ahead, the UK's biggest civil service union is expected to warn.
The PCS is threatening strike action after negotiations broke down
The Public and Commercial Services Union said a row over pay, job cuts and privatisation needed to be resolved.
On the eve of the TUC's conference in Brighton, union sources told BBC News wage negotiations had made no progress.
The government has said public sector wage rises need to be kept at less than 2% to help fight inflation.
Chancellor Gordon Brown told the BBC's Sunday AM programme private finance initiatives had "worked very well" and have led to more hospitals and schools.
But Mark Serwotka, general secretary of the PCS union, said there had to be a change of government policy rather than just a change of leader.
"If there is not a fundamental reappraisal of policies it will do nothing to resolve problems we are facing," he said.
The general secretary of the rail union RMT, Bob Crow, said he did not believe Mr Brown would be any more sympathetic to his union's demands as a prime minister.
"Gordon Brown has had an agenda - one of privatisation," Mr Crow said.
Unison general secretary David Prentis said Labour ran the risk of losing the next election if it did not halt the planned reforms.
Delegates at the TUC are thought likely to back a critical resolution supporting industrial action, a lobby of Parliament and a national demonstration.
BBC labour affairs correspondent Stephen Cape said: "A process will soon start to consult union representatives in every government department about a national strike, which could paralyse services across the UK later this year."
The deputy general secretary of the TUC, Frances O'Grady, said she is concerned about much of the public sector.
"It's not just the civil service; it's the health service and other areas of public provision where we think there's been too much dogmatic belief in the private sector being best," she said.
"We should be concentrating on making sure that public servants have the morale to provide the best services that we can."
TUC leader Brendan Barber said the health service could be disrupted by any strike action.
"In the NHS at the moment, there's a real mood of anger amongst the staff that wave after wave of change is being imposed," he said.
"The government needs to step back and begin to rebuild that relationship with its own workforce."