A strike is a work stoppage caused by employees’ refusal to work, typically to protest an employer decision (to close a plant, freeze wages, cut benefits, impose unpopular work rules, or refuse to improve working conditions, for example). The right to strike is protected by the National Labor Relations Act (NLRA), but not all strikes are legal. Whether a strike is lawful depends on the purpose of the strike, whether the collective bargaining agreement includes a “no-strike” clause, and the conduct of the strikers.
This article provides some basic information about legal and illegal strikes. For all of our articles on unions and labor, see our Labor Unions page.
A strike is legal – and therefore protected by the NLRA – if the employees are striking for economic reasons or to protest an unfair labor practice by the employer. In the first scenario, strikers are trying to get some economic concession from the employer, like higher wages, increased benefits, or better working conditions. In the second, workers strike because the employer has engaged in some practice that violates the NLRA, like refusing to bargain with the union or discriminating against union members. (See Unfair Labor Practices for more information.)
Even strikes with a legal purpose are not protected by the NLRA If the union’s contract with the employer (the collective bargaining agreement) includes a no-strike clause. With a few limited exceptions (for example, if employees are refusing to work because of unusually dangerous working conditions), a strike that violates a no-strike provision is illegal.
A strike can also become unlawful if strikers engage in serious misconduct, such as violence or threats, physically preventing other from entering or leaving the workplace, or sit-down strikes, in which employees refuse to leave the workplace and refuse to work. These strikes are not protected by the NLRA.
Although the NLRA protects the right to strike, employers don’t have to shut down for the duration of the walkout. Employers are legally allowed to hire replacement workers during the strike. Once the strike ends, the employer’s obligation to bring back striking workers depends on the reasons for the strike: