WASHINGTON (AP) — Labor Secretary Thomas Perez says the question of allowing college athletes to form unions "remains open" despite a federal ruling that this is impermissible.

Perez tells MSNBC's "Morning Joe" program there remains a key question about how workers "have a voice in the workplace."

Perez calls resolving that question part of government's "unfinished business." And he tells the network Tuesday that the government must continue to work for a society of "shared prosperity."

The National Labor Relations Board on Monday dismissed a NLRB regional director's 2014 ruling involving an organizing attempt at Northwestern University. The board concluded that having both union and nonunion teams could lead to different standards at different schools and create competitive imbalances throughout college sports. The ballots cast by players will be destroyed without being counted.