Thousands of workers from across the Midlands will strike and take other forms of industrial action today, in a protest over public sector pensions, pay and jobs.
Union leaders predict up to 400,000 workers across the country will be involved in a wave of demonstrations.
Among those taking part in today's action includes civil servants, health workers and lecturers.
Jobcentres, airports, tax offices, colleges, driving test centres, museums and military sites will all be hit by this week's strike.
The walkout follows last November's huge stoppage by over one-and-a-half million workers in protest at the planned changes to their pensions.
Up to 16,000 off-duty police officers, including those travelling from the Midlands, will take to the streets of London.
They are banned from striking under law but will hold a protest against proposed changes to their pay and conditions.
– Unite's assistant general secretary, Gail Cartmail
"[The] industrial action will build on the high level of anger that was on display during the November 30 strikes."Our members believe that the Government is attacking their pensions as a means of helping reduce the budget deficit, which has been caused by a greedy City elite, that has brought the economy to its knees. This is blatantly unfair."
Rallies will be held across the Midlands, including Birmingham, Telford and Nottingham.
– Minister for the Cabinet Office, Francis Maude
"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."In March we set out our final proposed agreement on pension reform following more than a year of intensive discussions with trades unions. Our reforms ensure that public sector pensions will remain among the very best available and that they can be sustained for the future."