Public sector workers across several different industries are striking this Christmas as they call for better pay and conditions.
Unions say most of the pay rises awarded earlier this year are not enough for people to live on, especially with the current high level of inflation.
As those in the public sector, of which there are about 5.7 million, receive taxpayers' money, the amount they are paid is determined by their overall employer - the government.
However, there is a lengthy process to determine their pay before ministers ever see a number.
The government chooses when it will respond to and publish the reports made by the pay review bodies.
Secretaries of state usually respond to the recommendations by issuing a written ministerial statement in parliament.
On the whole, the recommendations are accepted by secretaries of state, but there have been times when they have overridden the recommendations.
Sectors can disagree with the pay changes and can strike over the decision, but the government has the ultimate say.
Civil servants not in the senior civil service have their pay set by individual departments, according to guidance issued by the Cabinet Office and the Treasury.
Local government staff (not teachers) have their pay determined by their employers and trade unions.
Firefighters' pay is set by a separate body that is part of the National Joint Council for Local Government Services, which tends to follow the Treasury's public sector pay policy, although it is not bound by it.
Devolved governments - Northern Ireland, Scotland and Wales - set their own pay policy for public bodies under their control.