The Government last night was facing the threat of a pre-election strike by more than 1.5 million council workers and civil servants after massive votes for industrial action in a bitter row over pensions.
Five unions representing workers ranging from refuse collectors and school dinner ladies to Jobcentre workers and Customs staff said the overwhelming support for walkouts showed the strength of feeling.
A 24-hour stoppage will be held on March 23, crippling public services and closing schools, libraries, Jobcentres and council offices, unless the deadlock is broken in the next few days.
Last ditch talks between union leaders, employers and Deputy Prime Minister John Prescott will be held next week to try to avert the action.
The National Union of Teachers also announced plans to ballot its members on a one-day strike over Government plans to reform their pensions, threatening a second wave of strikes in April.
Unison, the Transport and General Workers Union, Amicus and Ucatt said their members voted in favour of strikes by majorities of between 73 per cent and 87 per cent.
The Public and Commercial Services union (PCS) later announced that its 270,000 members had backed strikes by 67 per cent.
The GMB said its balloting result will be known in the next few days and was expected to show similar support for industrial action.
The disputes were sparked by plans to raise the retirement age of public servants from 60 to 65 and make changes to pension schemes which unions said would make workers worse off.
Unison general secretary Dave Prentis said: "Our members who have paid their pension contributions week in, week out are very angry and are not prepared to accept changes by diktat.
"The average local government pension is just #3,800 a year - not a 'fat cat' sum. Low pay within councils means low pensions.
"Let's hope the employers see sense and abandon these changes so that real negotiations can take place."
Sir Sandy Bruce Lockhart, chairman of the Local Government Association said the system had to be changed but criticised the planned strikes.
"Local government must have a sustainable pension scheme which is fair to its employees and national and local council tax payers alike. The current scheme is unsustainable and changes must be made to secure it for the future," he said.
"Industrial action at this stage will do nothing to achieve this objective.
"Even now it is hoped that the unions will not take their proposed action so that constructive dialogue can take place with the Government."
Steve Sinnott, NUT general secretary, said: "The Government is not listening to teachers and other public service workers about the injustice of its proposals.
"I want members to support a one-day strike.
The NUT is the second teachers' union to ask its members to vote on whether to strike over the pension reforms.
Lecturers' union Natfhe decided last month to ballot members on action.