Over half a million workers in Britain are expected to strike on Wednesday. Unions from a variety of sectors will be participating in industrial disputes regarding pay, working conditions, and other issues.

These include the 300,000 English teachers who, according to the National Education Union, have seen at least a 23% real terms pay cut since 2010, teachers from two unions in Scotland, and around 100,000 civil servants working in more than 100 departments including coastguards and Department of Work and Pensions staff. There are also 70,000 university workers including security staff and lecturers; and approximately 100,000 bus and train drivers.

This widespread strike action has not occurred since the 2011 dispute over pay in the public sector. More than a million workers were estimated to have taken industrial action.

Tens of thousands will close or partially shutter schools, travel services and other services will be interrupted, and workers will organize hundreds of picket lines, rallies, and set up picket lines.

While demands vary from union to union, they include inflation-beating increases in pay, including to redress historical real-term pay falls; pensions reform; no reductions in redundancy terms. According to the NEU, teaching is in “crisis” because staff are being pushed from their profession. They also demand an above-inflational pay rise.

Protests will also take place over a bill passed in Parliament’s lower house on Tuesday. It seeks to establish minimum service levels in certain sectors and allows workers to be fired if the strike day demands it.

Trades Union Congress criticized the bill for being “wrong”, unworkable and almost certainly illegal.

Many unions hold several days of strikes. Some, such as rail, can last for months. The unions have co-ordinated Wednesday as a day for mass walkouts to convey a message.

This strike follows strikes by National Health Service nurses and ambulance drivers, who demand a raise in their pay. They also claim that labor shortages have made it nearly impossible to work.

Postal workers were also on strike and firefighters voted in favor of future strikes.

Between August and October, the average pay, excluding bonuses, rose by 2.7% in public sector. This was despite inflation exceeding 10%. According to national statistics, this is 6.9% less than the 6.9% increase in private sector pay.

Although inflation is starting to slow down, it remains high in historic areas and severe in those that have the greatest impact on workers with lower salaries. Inflation in grocery prices reached a record 16.7% during the four weeks ending Jan. 22.

CNBC was informed Wednesday by a spokesperson for the government that they had prepared to respond to any disruptions caused by Wednesday’s strike action. We have many contingency plans and have been ready to act in case of an emergency.

“Of course union bosses would prefer to cancel planned strikes and to continue talking to reach an agreement.