Bombay Industrial Relations Act (extended to Gujarat), 1946
An order, decision or award of the Industrial Court shall be binding on— (a) all parties to the industrial dispute ; (b) all parties who were summoned to appear as parties to the dispute whether they appeared or not unless the Industrial Court is of opinion that they were improperly made parties ; (c) in the case of an employer who is a party to the proceeding before such Court in respect of the undertaking to which the dispute relates, his successors, heirs or assigns in respect of the undertaking to which the dispute relates; and (d) in the case of a registered union which is a party to the proceeding before such Court, all persons represented by the union at the date of the award, as well as thereafter.