The Government is facing the biggest outbreak of industrial action since it came to power after civil servants joined teachers in voting heavily for strikes in worsening rows over pensions, pay and jobs.
Up to 750,000 public sector workers will stage a 24-hour walkout on June 30, with civil servants then embarking on a month-long ban on overtime.
The action could spread later in the year to other parts of the public sector, including councils and the NHS, threatening an autumn of discontent involving more than 1.5 million workers.
Members of the Public and Commercial Services union voted by 61.1% in favour of strikes, and by 83.6% for other forms of industrial action, in a turnout of 32.4%.
The union is protesting at planned changes to pensions as well as job cuts and a pay freeze for civil servants as part of the Government's austerity measures.
The news followed huge strike votes yesterday by members of the National Union of Teachers (NUT) and the Association of Teachers and Lecturers (ATL) over pensions.
More than 300,000 teachers were balloted in total, and the walkout is set to be the biggest day of action by teachers in decades.
ATL has never taken national strike action in its 127-year history, and the last time it took national industrial action was in 1979, before current legislation on balloting, over changes to teachers' pay.
Cabinet Office minister Francis Maude said it would be a "big mistake" for teachers and civil servants to go on strike while negotiations were still continuing, with fresh talks planned for later this month.
The Department for Education said a strike "will only damage pupils' learning and inconvenience their busy working parents".
The teaching unions say the Government's proposed pension changes will see them work longer, pay in more and receive less when they retire.
ATL president Andy Brown said: "It is with deep reluctance that I announce the date for ATL's first ever national strike.
"We have carefully picked this date to avoid external exams and important school and college events so that any strike causes as little disruption as possible to children's education.
"We do not want to strike, but unless we take a stand now, the Government will irreparably damage education in this country and children will lose out."
NUT general secretary Christine Blower said: "Teachers do not take strike action lightly but the overwhelming support for action by NUT members shows that teachers feel what is happening to their pensions is wrong.
"The NUT will continue to take part in the TUC-led negotiations with Government on pensions. So far there is no evidence that the Government is taking those talks seriously. We hope that our action and that of the ATL will persuade the Government to change its attitude."
Results from the NUT's ballot showed that 92% were in favour of strike action.
Turnout was 40% among state school members of the union and 27% among private school members.
Some 83% of ATL members voted to strike, and overall turnout for the ballot was 35%.
University lecturers will also take industrial action on June 30, while direct action group UK Uncut said it will stage protests on the same day to coincide with the strike.
Meanwhile, talks aimed at averting a series of strikes by London Underground workers in protest at the sacking of a driver broke down today.
The Rail Maritime and Transport union accused Tube bosses of refusing to discuss the reinstatement of the driver, Arwyn Thomas, who has taken a claim of unfair dismissal to an employment tribunal, with the result due by the end of the month.
The union is planning a series of strikes, starting this Sunday evening, which will hit the Wimbledon tennis championships.
Both sides met at conciliation service Acas for two hours today, but the RMT said the talks had broken down and the strikes were now set to go ahead.
PCS leader Mark Serwotka said: "This result shows that public servants, who provide vital services from the cradle to the grave, will not stand back while everything they have ever worked for is taken from them.
"The Government admits that money cut from pensions will go straight to the Treasury to help pay off the deficit in what is nothing more than a tax on working in the public sector. The very modest pay and pensions of public servants did not cause the recession, so they should not be blamed or punished for it.
"Unless ministers abandon their ideological plans to hollow out the public sector, they will face industrial action on a mass scale on 30 June and beyond."
He said the mandate was "convincing" and accused the Government of "lying" over the effect of the pension changes.
Around 100,000 civil servants faced losing their jobs on top of a two-year pay freeze and worse pensions, he said.
He predicted that three or four million public sector workers could be involved in strike action by the autumn and described talks with the Government as a "farce".
He added: "The Government should stop lying and come clean about what they are doing. This is a vote to try to force the Government to engage with us and stop this outlandish attack on workers."Reuse content