Unions evolved as a way for workers to join together to face the power that an employer has as the owner or operator of a business. The inequality of bargaining power between a worker and employer can be evened up in this way. As long as an employer is dealing with one employee, the balance of power is with the employer. When the employer is dealing with an organization that represents all employees, there is less power imbalance. One of the few threats available to a worker in a disagreement with an employer is the withdrawal of labour, known as a strike. The threat or reality of a withdrawal of labour is greater if the whole workforce is involved rather than one person. The timing of strike action is just as crucial as the fact of a strike itself. A union could plan to take strike action at a point when it would be crucial for an employer to have the business running. Strike action is arguably most effective if it happens when an employer has no contingency plans in place. If a requirement of delaying strike action is introduced, a union might be seen to have lost a valuable advantage. March 2016