Further strikes are planned by union leaders in the autumn after a co-ordinated day of industrial action over pay, pensions and cuts to services supported by hundreds of thousands of public sector workers.
Union chiefs hailed the action a success, claiming that around 6,000 schools shut for the day or had partially closed, while local government workers, civil servants and firefighters joined the action.
Unions said that more than 1 million workers, including 200,000 teachers, walked out yesterday, but the Government insisted the figure was less than 500,000.
At a rally in central London, unions signalled the strikes could even continue into the New Year and the run-up to next May’s general election.
The action could resume in September with two nationwide walk-outs amid suggestions that health service workers could swell the numbers in the protests.
The Government and town hall leaders insisted yesterday’s action had only been backed by a small minority of activists, while Tory ministers repeated their determination to tighten the rules on strikes in essential services.
With no sign of a thaw in relations between the two sides, leaders of local government unions will meet shortly to discuss tactics in their fight against a one per cent pay rise.
One source said: “We’ve still got a mandate for action.”
The National Union of Teachers (NUT), which is protesting over performance-related pay, higher pension contributions and increased workload, said it would consider its next step in the autumn.
Meanwhile, members of the Fire Brigades Union are due to strike on eight consecutive days starting on Monday in a continuing wrangle over pensions.
Yesterday’s action hit schools in England and Wales, with teaching assistants, caretakers and other school staff backing the NUT action.
Museums, galleries and courts were also affected and around one-fifth of driving tests were cancelled.
Unions said more than 1200 picket lines were set up outside town halls and council depots and protest rallies were held in large cities across the United Kingdom.
All business was cancelled at the Welsh Assembly, around 900 civil servants walked out in Scotland and Belfast Zoo and leisure centres were among amenities which shut in Northern Ireland.
The Cabinet Office minister Francis Maude told MPs: “When unions go on strike, it is hard-working people who suffer the consequences most, including vulnerable people who depend on public services and parents who are forced to take a day off work or arrange child care because their local school is closed. These strikes risk damaging those who are working hard to get this country moving again.”
David Cameron yesterday confirmed the Conservative Party would promise new laws in its election manifesto to limit strikes in public services. It is considering outlawing strikes when union ballots authorising action fail to reach a turn-out threshold.
His spokesman suggested the Prime Minister believed strikes in public services could never be justified.
But the Labour leader Ed Miliband accused the government of demonising public service workers by “ramping up the rhetoric” against them. He said: “The answer is to get round the table and prevent further strikes happening.”
Christine Blower, the NUT’s general secretary, the largest teachers’ union, said: “We believe over 50 per cent of schools have been affected by the action through either complete closure or part closure.
“Extraordinarily the Government’s response to today’s action has been to completely ignore the issues and instead seek to reduce people’s right to strike.”
The Local Government Association said the impact on essential council-run services had been relatively small.
It claimed only one in 20 council staff had joined the strike action, with around 95 per cent reporting for work as usual yesterday.
An LGA spokesman said: “Local authorities have put contingency plans in place to ensure that residents notice as little disruption as possible.
“Most of our staff are at work today, continuing the fantastic job they do of running the services on which people rely.”
TUC general secretary Frances O’Grady: “Today's well-supported action shows just how angry public servants are at plans to lock them out of sharing in the recovery until at least 2018. Nearly half a million local government workers are paid less than the living wage - it is time they shared in the growth that ministers trumpet.”
Unison general secretary Dave Prentis: “The strength of feeling amongst our local government and school support workers over the issue of pay was plain to see today. The decision to take strike action and sacrifice a day's pay was a very difficult one, particularly for the hundreds of thousands of low paid workers, but our members felt this was the only way to have their voices heard.“
Christine Blower, NUT general secretary: “The reason why this dispute is so long running is due to the absolute failure of this Government to engage in any meaningful discussions on the main issues of our dispute. The responsibility for today’s action lies fairly and squarely at the door of Government. “
Unite general secretary Len McCluskey: "It is utter hypocrisy for the Government to talk about mandates for trade unions when not a single member of the present Cabinet would have been elected using the same criteria.
"This Government has no mandate to attack trade unions or the workers who have been forced to take industrial action today in their fight to end poverty pay."
Lib Dem Business Secretary Vince Cable: “We believe that getting round the negotiating table is better than striking.
"We do not believe unions should be striking and causing mass disruption when everyone has been affected by similar pay conditions.Reuse content