Definition:
A requirement by the NLRB that must be met by a union when a union wishes to represent a group of employees. There are several showing of interest requirements used by the NLRB: (1) A petitional union needs 30% of the eligible members in the union; (2) Where a union has petitioned and another union wishes to intervene, the second union must have 30% of the unit it seeks; (3) Where a union petitions and another union wishes to intervene in the same unit to the extent of blocking a consent election agreement, it must have 10%; (4) Usually, a showing of one or two cards is enough for a second union to intervene only to have their name on the ballot or to participate in a hearing; (5) A current or recently expired contract is also a criterion for showing of interest.