Negotiations between an employer and the union have proceeded without success. The union has told its members to walk off the job. The employer has forbidden any union members who want to report for work from being admitted to the workplace premises. Which employer practice does this example demonstrate?

Constructive discharge refers to a situation where an employee feels compelled to resign due to intolerable working conditions created by the employer. In this case, the employer's actions do not force employees to resign; rather, they are actively preventing them from working, which does not fit the definition of constructive discharge.

A wildcat strike is an unauthorized work stoppage initiated by employees without union leadership's approval. The current situation involves the union instructing its members to walk off the job, which is not a wildcat strike since it is a sanctioned action rather than an unsanctioned one.

Retaliatory termination occurs when an employer fires an employee in response to the employee's protected activities, such as union involvement. Here, the employer is not terminating employees but implementing a lockout, so this term does not apply to the scenario described.