party (NLRB Act § 11(1))

The Act does not define the term 'party'; but it does make clear that the role of the General Counsel is a major one. By § 3(d) of the Act he is given 'final authority' respecting the investigation of charges, the issuance of complaints, and the prosecution of complaints before the Board. The General Counsel is, indeed, indispensable to the prosecution of the case. He vindicates the public interest, performing functions previously performed by the Board itself. Plainly the issuance of subpoenas may often be essential to the performance of that role. To relegate him to a lesser role than that of a 'party' is to overlook the critical role he performs in enforcement of the Act.

Defined by the Supreme Court in - Lewis v. National Labor Relations Board, 357 U.S. 10 (1958).