Here we have the classic overreach: a union, not happy with an American decision, decides to skip appealing to the courts under American Labor law, and go to a panel of the UN, a nonprofit in New York City, instead.
Will this be effective? Well, not to gain the union any goodwill. There have been reports of dropped memeberships, with apologists for the union not addressing representation issues. Should Congress step in? Perhaps to legislatively decertify the union from representing federal employees?
UPDATE:Even federal civil servants are unhappy about this one in large numbers.