The National Labor Relations Act ("NLRA") forbids employers from interfering with, restraining, or coercing employees in the exercise of rights relating to organizing, forming, joining or assisting a labor organization for collective bargaining purposes, or engaging in concerted activities, or refraining from any such activity.

Concerted activities which are protected include joining with others to modify wages or working conditions.

Conduct which is prohibited includes threatening employees with loss of jobs or benefits if they join or vote for a union or engage in protected concerted activity; threatening to close the plant if employees select a union to represent them; questioning employees about their union sympathies or activities in circumstances that tend to interfere with, restrain or coerce employees in the exercise of their rights under the Act; promising benefits to employees to discourage their union support; and transferring, laying off, terminating or assigning employees more difficult work tasks because they engaged in union or protected concerted activity.

The NLRA is enforced by filing a complaint with the National Labor Relations Board ("NLRB"). A complaint must generally be filed within six months of the illegal conduct. Employees and employers can be represented by attorneys in proceedings before the NLRB.