A coalition of conservative groups urged Senate lawmakers to oppose the renomination of Mark Gaston Pearce to the National Labor Relations Board, the main federal labor enforcement agency, saying that Pearce was responsible during his tenure as chairman for turning the NLRB into a partisan entity rather than a neutral arbiter of policy.

The plea comes as pressure is being brought to bear by Democratic lawmakers to get two of Trump’s appointees to the five-member board, Chairman John Ring and William Emanuel, to recuse themselves from a wide swath of cases, a move that would functionally give the board a Democratic majority if Pearce stayed on.