A fresh wave of industrial action will be held this week against the Government's controversial public sector pension reforms, with union leaders predicting that up to 400,000 workers could be involved.
Civil servants, lecturers, health workers, Ministry of Defence staff, immigration officers, off-duty police officers and members of the Royal Fleet Auxiliary will be among those joining strikes and other forms of protest on Thursday.
Most public sector unions remain opposed to the reforms, which they warned would leave millions of workers having to pay more into their pensions, retire later and receive less when they stop work.
Off-duty rank-and-file police officers will also march through central London on Thursday, passing by the Home Office, in a protest over proposed changes to their pay and conditions. Along with the armed forces and prison officers, the police are banned in law from taking industrial action.
Many officers are angry with the Government in the wake of 20% budget cuts and proposals for the most wide-ranging reform of police pay and conditions in more than 30 years.
The Police Federation said its protest would show "the unprecedented attack on policing by this Government and the consequences that these cuts will have for public safety". Ministers insist the current level of public sector pensions is unsustainable and reforms are needed, saying workers will still receive decent payments on retirement.
Mark Serwotka, general secretary of the Public and Commercial Services union, said: "The coalition has reduced tax for super-earners while making cuts to vital public services like Jobcentres, borders and tax collection.
"Public sector workers have seen thousands of their colleagues sacked, their pay has been frozen for two years, and they are being told they must pay much more, and work for up to eight years longer for smaller pensions. That's why hundreds of thousands of workers will be striking on Thursday in opposition to the Government's prescription of austerity and misery that has plunged the UK back into recession."
Jobcentres, airports, tax offices, colleges, driving test centres, museums and military sites will all be hit by this week's strike. Picket lines will be mounted outside Government buildings, Parliament, museums and galleries, while rallies will be held across the country, including London, Birmingham, Glasgow and Liverpool.
Minister for the Cabinet Office, Francis Maude, said: "It is very disappointing that a minority of union insist on carrying on with a futile and disruptive strike action which will benefit no one. We would urge union leaders to reconsider their position. Pension talks will not be reopened and members are risking losing a day's pay for nothing."