LONDON, England - March 1, 2009 - Top-secret contingency plans have been drawn up to counter the threat posed by a “summer of discontent” in Britain.

The “double-whammy” of the worst economic crisis in living memory and a motley crew of political extremists determined to stir up civil disorder has led to the ­extraordinary step of the Army being put on standby.

MI5 and Special Branch are targeting activists they fear could inflame anger over job losses and payouts to failed bankers.

One of the most notorious anarchist websites, Class War, asks, “How to keep warm ­during the credit crunch? Burn a banker.”

Such remarks have rung alarm bells in Scotland Yard and the Ministry of Defence.

Intelligence sources said the police, backed by MI5, are determined to stay on top of a situation that could spiral out of control as the Depression bites deep.

The chilling prospect of soldiers being drafted on to the streets has not been discounted, although it is regarded as a last resort.

What worries emergency planners most is that the middle classes, now struggling to cope with unemployment and repossessions, may take to the streets with the disenfranchised.

The source said, “this potent cocktail is reminiscent of the poll tax riots that fatally wounded Margaret Thatcher’s government in 1990”.

Last night, Scotland Yard vowed it was ready to face any threat. An unnamed source said, “We do have a policing plan in place and we have riot police officers trained for such measures.”

But other senior police leaders fear the force will be unable to cope.

Were that to be the case, the government has a contingency plan to deploy troops on the streets of Britain’s major cities.

A senior source said, “This is a very real, and very serious, problem. I can tell you there have been crisis talks in Whitehall about this. Half the senior officers in Britain have been warning the Home Secretary about the dangerous effects that reducing police manpower may have this summer, especially in the industrial heartlands. We are not just talking about the problems of immigration and British jobs for British workers. We are also talking about mass unemployment.

“In many of our industrial cities, this will not be measured in the hundreds, but in the thousands. With unemployment comes the risk of increased crime. Some forces, such as South Wales, have publicly ­stated they would be swamped. Others are keeping it quiet, but you can be sure they are trying to make the Home Secretary listen, ­before it’s too late.”

The “protest season” is due to ­begin on April 1 with the G20 Summit in London next month, followed by the 60th anniversary of NATO in Strasbourg a few days later. May Day is also ­potentially a flashpoint.