Police have been checking the identification of picketers to make sure they are union members and not anarchists.

They were seen asking for identification outside the job centre in Kingston, where workers are staging a 24-hour strike against planned changes to pensions.

The job centre is open as normal, despite 75 per cent of its workforce being unionised.

Stan Stennett, branch chairman of the Public and Commercial Services Union, said: “A lot of us feel bitter at this government. I started 25 years ago and I was in a scheme that would give me a pension when I’m 60.

“Now they are saying they want to give us something less and are asking us to pay more in to it.”

More to come.