Union leaders and ministers have clashed over the impact of a strike by public sector workers who mounted picket lines outside schools, Government buildings, job centres and courts.
The Public and Commercial Services union (PCS) claimed it was the "best-supported strike" they have ever had, but the Government questioned the numbers taking part. The Cabinet Office said early signs were that less than half of PCS members took part in the strike.
Downing Street said there had been no significant delays at borders and no disruption at airports despite fears that travellers would be hit as immigration staff joined the 24-hour walkout.
Hundreds of thousands of teachers, lecturers, civil servants and other public sector workers were staging a 24-hour strike in protest at the Government's plans to increase their pension contributions and raise the retirement age. The action has forced the closure of thousands of schools, courts and offices and disrupted Government services and travel.
More than 11,000 schools in England were affected by the strike, according to the latest figures from the Department for Education. Members of the National Union of Teachers, Association of Teachers and Lecturers, University and College Union and the PCS were taking action.
PCS general secretary Mark Serwotka, said: "This is the best-supported strike we've ever had."
The Prime Minister's official spokesman described the strike as "unnecessary and premature", adding: "There is this debate that is raging about unaffordable versus untenable. The fact of the matter is this was looked into very thoroughly by Hutton and he concluded that we needed to reform public sector pensions."
Labour leader Ed Miliband said: "These strikes are wrong at a time when negotiations are still going on but parents and the public have been let down by both sides because the Government has acted in a reckless and provocative manner. "
TUC general secretary Brendan Barber accused the Government of unfairly "hammering" millions of low and medium-paid public sector workers by piling the burden of reducing the country's debts onto them.
But he also criticised Labour for a lack of support in not speaking up strongly enough in defence of the current pension plans agreed when they were in government.