Definition of 'Unofficial Strike'
A work stoppage by union members that is not endorsed by the union and that does not follow the legal requirements for striking. Workers engaging in unofficial strikes have little legal recourse if they are fired and do not receive strike pay.
Also called a "wildcat strike" or "unofficial industrial action."
Investopedia explains 'Unofficial Strike'
Well-known unofficial strikes include the 2007 unofficial Royal Mail postal strike in the