The National Labor Relations Board (NLRB) reaffirmed Thursday that the Student Library Employee Union’s (SLEU) right to unionize would not be at issue in an ongoing NLRB case over UChicago student library workers’ vote to unionize last year.

The decision rejected a University request to review the issue, finding no “extraordinary circumstance” warranting a reversal. The NLRB ruling now leaves only a charge of electioneering between SLEU and official union recognition.

The Board ruled in December that a hearing should be conducted about SLEU’s conduct during the vote; if sufficient misconduct is found, it could warrant a new election.

The decision—by NLRB members Marvin Kaplan, Mark Pearce, and William Emanuel—also rejected the University’s request for a stay in the proceedings. In the stay request, the University argued that the Board should first rule on graduate assistants’ unionization cases at Chicago and other universities.

Although SLEU’s standing is settled in UChicago’s case, the Board may still review undergraduate unionization. Former Board Chairman Miscimarra, who concurred in rejecting the University’s earlier motion, has indicated openness to hearing further challenges in a different case.

Thus, if another school saw undergraduate organizing, the NLRB could still use that case to reverse itself.

Grinnell College’s undergraduate dining workers signed a contract in 2016, but Grinnell never challenged the result, meaning the NLRB did not render a decision on the union’s status.

This is the first NLRB case explicitly about the status of an undergraduate worker unions, though past decisions on graduate workers have discussed the issue.