The NLRB recently announced a proposal to broaden the legal standard used to determine joint employers in order to address modern labor issues regarding contract work. Joint employment occurs when two companies share legal liability regarding their employees and union bargaining obligations. However, changing the joint employment standards would impact business relationships, and many industry groups are in opposition of such a change.
See "NLRB plans to eliminate strict joint employment standard", Robert Iafolla, Bloomberg Tax, September 8, 2022