After receiving a large order, the shipping supervisor of a unionized manufacturing plant informs the crew that an overtime shift will be scheduled for the following Saturday. Three of the employees strongly object but do not provide acceptable excuses for not working the extra shift. On Saturday, none of the three employees report to work and the supervisor is forced to call out replacement employees from other departments. On the following Monday, as part of an investigation to determine if disciplinary action is called for, the supervisor instructs each of the employees to report alone to the office immediately after their shifts. The supervisor’s intention is to question them about their failure to report for the overtime shift as required.

The supervisor would be engaging in what could be deemed an unfair labor practice by failing to: