A winter of strike action by more than a million public sector workers is poised to move a step closer.
The walkouts would be in protest at planned changes to pensions, which will see contributions increase by 3.2%.
An announcement of co-ordinated action is likely to be made following a debate at the TUC Congress in London, when unions will line up to attack the Government.
Widespread ballots for action are expected to be held, adding to support for strikes already given by civil servants, teachers and lecturers, heralding the biggest outbreak of industrial unrest for decades.
Plans to co-ordinate industrial action will be discussed at the TUC, but sources said a large number of unions were now moving towards balloting for strikes.
Francis Maude, the Cabinet Office minister who is leading negotiations for the Government, said he was not trying to provoke unions into industrial action, adding that any strike call will be greeted with little enthusiasm from workers and even less sympathy from the general public.
"We don't want strikes and the public will be very fed up if there are widespread strikes which close schools and affect health services and transport. People who are struggling to pay their bills and paying more towards public sector pensions in many cases than they are paying towards their own pensions will be mightily fed up if there is unnecessary strike action," he said.
Labour leader Ed Miliband was heckled on Tuesday when he told the TUC Congress that strikes over public sector pensions were a mistake. He said he understood why millions of workers were angry, adding: "But while negotiations were going on, I do believe it was a mistake for strikes to happen. I continue to believe that.
"What we need now is meaningful negotiation to prevent further confrontation over this autumn. Strikes are always the consequence of failure. Failure on all sides. Failure we cannot afford as a nation. Instead your real role is as partners in the new economy."
Mary Bousted, leader of the Association of Teachers and Lecturers, said she had been proud to join a strike in June by tens of thousands of teachers and civil servants and told Mr Miliband that the Government was not prepared to negotiate a deal over its planned pension reforms.