Who replaces a worker gone on strike?

A very political situation. When strike action occurs it is hoped by a controlling union that all employees will "down tools" and stop work. However, since the 1970's the role of unions has according to some diminished as less and less people join a body.

When a strike is called it is now possible that non union workers will be told to take on the roles left open until the strike is over. Many names have been used to describe these people who, only try to stay employed and earn a wage. Terms used are strike breakers, scabs (heard in the UK during the 1980's when the collieries went on strike). The "closed shop" where a union is fully supported by a 100% employee membership has long since disappeared. Some organisations have introduced no strike rules, employed agency staff who are on rolling contracts and are not eligible to join a union or strike