As private-sector union membership tanks, the current administration continues its push for those it says are “unaware.”

In a move that could help boost union ranks, the National Labor Relations Board on Tuesday proposed a new rule requiring private-sector employers to post notices telling workers about their right to unionize.

The proposal is sure to please labor groups concerned about a decline in union membership, but could draw complaints from businesses wary of workers trying to organize under their nose. Under the rule, businesses would have to inform their employees about their union rights regardless of whether a union already exists in the workplace.