Strike ballot,

Definition of Strike ballot:

1. Secret ballot conducted among the members of a union to determine whether to go on a strike, and decided by a clear majority. In most jurisdictions, (1) both the intention to proceed with the strike ballot and the strike itself must be communicated to the employer at least seven days before proceeding with the either, and (2) the strike ballot must be subject to independent verification where the number of employees exceeds a certain figure (commonly 50). See also strike vote.