Tens of thousands of civil servants are set to vote on whether to launch fresh strikes in the new year in bitter disputes over pay and conditions.
The executive of the Public and Commercial Services (PCS) union drew up a timetable for voting among over 250,000 of its members unless ministers ended "attacks" on working conditions.
The union is pressing for an end to a pay freeze for civil servants, pay rises of £1,200 or 5%, the introduction of the living wage on government contracts and no cuts to pensions.
PCS leaders will meet again next month to assess the Government's response and make a final decision on the timing of a strike ballot.
The union has been embroiled in disputes all year with the Government over jobs, pay and pensions, with a new row flaring over plans to change terms and conditions of civil servants.
The PCS has warned of further cuts to civil service budgets which it said will spark more job losses on top of the 63,000 that have gone since the coalition was formed.
General secretary Mark Serwotka said: "While we will seek meaningful negotiations, we cannot and will not sit and watch this Government undermine everything we have ever worked for, and we are committed to preparing for industrial action if necessary.
"George Osborne's disastrous management of our economy was laid bare in his autumn statement and we will continue to take every opportunity to oppose his government's failing obsession with austerity, and to campaign for the alternative of investment to improve our public services and revive our struggling communities."