At prime minister's questions, David Cameron accuses the Labour leader of 'leftwing' support for the strike Link to this video

Trade unions and the government have traded blows over the impact of the biggest outbreak of industrial unrest in three decades, as up to 2 million public sector workers went on strike, forcing the closure of 62% of state schools in England and the cancellation of 6,000 hospital operations.

Heathrow airport reported minimal disruption as the mass rebooking of passengers helped reduce queues at border control, but the cabinet secretary, Francis Maude, acknowledged that the strikes over pension reforms had disrupted services. The impact includes:

• 19,000 out of 21,700 schools in England and Wales closed or partially closed.
• 6,000 out of 30,000 non-urgent operations cancelled.
• 135,000 civil servants on strike, representing just over a quarter of the civil service.

With the strike only halfway through, the prime minister and Labour leader battled to make political capital out of the unrest. At prime minister's questions in the House of Commons, David Cameron claimed that the strikes had failed to have a significant impact.

"At our borders the early signs are that the contingency measures are minimising the impact, we have full cover in terms of ambulance services, and only 18 of the 900 job centres are closed," he said. "So despite the disappointment of the party opposite, who support irresponsible and damaging strikes, it looks like something of a damp squib."

Ed Miliband said the government must accept blame for the strikes. He asked Cameron: "Why do you think so many decent, hard-working public sector workers, many of whom have never been on strike before, feel the government simply isn't listening?"

Maude said the strikes were irresponsible as he disputed union claims that talks over pension reforms had ground to a halt. One of the main union negotiators, however, the GMB's Brian Hutton, said discussions on the four pension schemes – health, education, civil service and local government – had either stalled or were insubstantive. "In most of the schemes there is really nothing going on at all," he said.

A spokesman for the TUC, which is co-ordinating the strikes, said up to 2 million workers had taken part in the biggest bout of industrial action since the 1979 winter of discontent.

"There has been magnificent support for the strike today. It is the biggest in a generation."

Referring to government claims of a low turnout and deliberate disruption of negotiations, the spokesman added: "The government is clutching at straws. The real question remains, how did this government provoke so many ordinary, decent people to go on strike for the first time in their lives?"

Mark Serwotka, the leader of the Public and Commercial Services (PCS), said reports from picket lines showed a huge turnout, with up to 90% of staff in some government departments, including Revenue and Customs, taking action. "I have been to pickets around central London and spirits are sky-high, with many other unions besides PCS out on strike," he said."

Britain's largest airport, Heathrow, reported no disruption as the busiest time of day for passport control and international arrivals at 7am passed without incident. Some 60,000 passengers normally pass through border control at Heathrow on a normal day, but major airlines including British Airways and Virgin Atlantic indicated that thousands of travellers had rebooked to an alternative date free of charge.

"Due to the effective contingency plans we have put in place with the airlines and the UK Border Agency over recent days, immigration queues are currently at normal levels," said the airport's operator, BAA. British Airways, Heathrow's largest customer, said passenger numbers were reduced compared with an average day while Virgin Atlantic said it was operating at 50% capacity.

Michael Gove, the education secretary, said that the action has had a "severe impact on schools across the country".

He released figures that showed 62%, (13349) of the country's 21,476 state funded schools in England had closed, with a further 3,351 (16%) only partially open, and 16% open as normal. The situation at the remaining 1825 schools is unknown.

Gove said: "Industrial action, today...has caused disruption to children's schooling and to parents and employers. At the same time, we know that many dedicated professionals have worked hard to keep schools open where they could."

Downing Street delivered a further update to journalists on the impact of the walkout. Rajeev is sending this.

In Scotland it was thought just 30 of the 2,700 council run schools remained open. In Wales around 80% were believed shut and in Northern Ireland more than 50% of 1,200 schools were closed.

NHS managers estimated that some 6,000 out of 30,000 routine operations had been cancelled across the UK, as well as tens of thousands of appointments. The health secretary, Andrew Lansley, said patients who had operations cancelled would still be seen within an 18-week limit.

London Ambulance Service told BBC London it was struggling and people not in a life-threatening condition might not get an ambulance.

The strike saw walkouts by tens of thousands of border agency staff, probation officers, radiographers, librarians, job centre staff, court staff, social workers, refuse collectors, midwives, road sweepers, cleaners, school meals staff, paramedics, tax inspectors, customs officers, passport office staff, police civilian staff, driving test examiners, patent officers and health and safety inspectors.

In Wales unions reported around 170,000 workers on strike, and in Scotland around 300,000.

Up to 1,000 marches and rallies were due to take place across the UK. Four arrests were made ahead of a national rally in London, two for assaulting an officer and two for possession of a weapon.

Unite general secretary Len McCluskey, who was due to address the London rally later, said 30 November would go down as the day when the union movement and workers fought to protect the economic and welfare advances of the last 60 years. Working people were "being asked to pay for the economic mess caused by the greedy City elite whose behaviour this spineless government has repeatedly failed to tackle", he said.

Touring picket lines in London, he added: "The action today has been a brilliant display of courage and concern by public servants who are being demonised by a government that has lost its moral compass."

In Salford, Greater Manchester, around 20 council refuse collectors were gathered around a brazier waving placards, one of which read: "Do we look Gold Plated?". Unite organiser Neil Clarke said: "I don't think George Osborne could find Salford if you gave him a map."

Outside Edinburgh's Royal Infirmary nurses, lab workers and cleaners were joined by the veteran trade union leader Rodney Bickerstaff, a pivotal figure in the 1970s.

"These are people who work day in, day out. They wipe noses, they wipe bottoms, they teach unruly kids, work with dustbins and sewage works. They are services which civilise our society," he said.

In Liverpool Inspector Russ Aitken from Mersey Tunnel police was taking industrial action for the first time in 35 years. "I feel angry that I'm paying a 50% increase in pension contributions and I feel angry that I'm going to have to work longer and at the end of it get less."

Outside the Crown Prosecution Service office in Manchester city centre, a handful of lawyers were among those manning the picket line. The average annual pay of a CPS solicitor was £30,000 rising to £50,000, said strikers, but many low pay grade civil servants would get average annual pensions of £5,600 after 40 years service.

Courts across the UK were affected, said Norina O'Hare, who represents the justice and prosecutions sector of the PCS. "We've had a lot of support from judges who are, of course, also public sector workers."