Video: Damp squib, says Cameron as teachers and nurses join picket lines

Unions have described the strike by up to two million public sector workers as “historic” after walkouts closed down schools, courts, museums and JobCentres and disrupted transport, hospitals and Government departments.

But Mr Cameron branded the industrial action “irresponsible and damaging” and told the House of Commons that support among public sector workers had been far from universal.

“I want to thank all those people, including a number of people from 10 Downing Street, who are helping to keep our borders open and make sure Heathrow and Gatwick are working properly,” Mr Cameron told MPs at Prime Minister’s Questions.

“So far the evidence would suggest that around 40% of schools are open and less than a third of the civil service is actually striking.

“On our borders the early signs are the contingency measures are minimising the impact. We have full cover in terms of ambulance services and only 18 out of 900 JobCentres have closed.

“Despite the disappointment of the party opposite, that support irresponsible and damaging strikes, it looks like something of a damp squib.”

Schools, hospitals, courts and transport were hit by the strike as teachers, nurses and civil servants joined weather forecasters, botanists and nuclear physicists on picket lines.

Hospital employees and workers on the Mersey tunnels were among the first to take action from midnight, setting up picket lines and holding up banners attacking the Government’s pension reforms.

Early Government figures suggested that almost three in four schools were affected by the walkout, although that number could rise.

The Department for Education (DfE) said it believed that more than half of England’s 21,700 state schools (58%) were closed, with a further 13% partially shut. Around 13% are open, the DfE said, while the rest are unknown.

Schools in Scotland, Wales and Northern Ireland are also expected to be affected.

Queues are expected to build up during the day at Heathrow airport, no ferries will sail to or from Shetland, and the Metro in Newcastle will not run.

Cabinet Office minister Francis Maude launched fresh criticism of the strike today, saying it was “inappropriate, untimely and irresponsible”, especially while talks were continuing.

“Responsibility for any disruption which people may experience today lies squarely with union leaders. We have listened to the concerns of public sector workers and that is why at the beginning of this month we put an improved offer on the table.

“The offer ensures that public sector pensions will remain among the very best available while also being fair and affordable to taxpayers.

“While discussions are continuing, I would urge public sector workers to look at the offer for themselves rather than listening to the rhetoric of their union leaders. These are the sort of pensions that few in the private sector can enjoy.

“This morning, I want to reassure the public that we have done everything we can to minimise disruption. Rigorous contingency planning is in place across all sectors to try and limit the impact of the strike action and to ensure that key public services remain open.

“However, we now estimate today that around three-quarters of schools in England will be closed or partially closed today. Council services such as refuse collection, street cleaning and libraries are also likely to be affected.”

Employees at Birmingham Women’s Hospital in Edgbaston were among the first public sector workers to walk out at midnight, setting up picket lines which will be manned for the next 24 hours.

Unison president Eleanor Smith, who is a theatre nurse at the hospital which employs around 400 union members, said: “This has not been a decision that I’ve taken lightly. I have been a nurse for 30 years and this is the first time I have been compelled to take this action because of the Government.

“The Government wants us to work longer, pay more and at the end get less. How fair is that?”

The nurse added: “I came into the public sector not for great wages but for a pension. Now this pension which I was relying on is going to be taken away - not totally, but considerably reduced. I get the impression the Government doesn’t like the public sector.”

Among those walking out at the Mersey Tunnels was Inspector Russ Aitken from Mersey Tunnel Police, who is taking industrial action for the first time in 35 years.

“I feel quite strongly that I need to come out on strike,” he told BBC Radio 5 Live.

“I feel angry that I’m paying a 50% inc