89(1)The Board may in its discretion, or at any time following the release of an order or direction under section 83 or 88, alter the bargaining unit determined in a certificate or defined in a collective agreement as it deems proper, and the certificate or agreement, as the case may be, shall be deemed to have been altered accordingly.

89(2)The Board may, upon the application of any person, employer, trade union, council of trade unions or employers’ organization affected by a decision of a tribunal referred to in section 85, alter the bargaining unit determined in a certificate or defined in a collective agreement as it deems proper to enable the parties to conform to the decision of the tribunal, and the certificate or agreement, as the case may be, shall be deemed to have been altered accordingly.

89(3)Where an employer is a party to or is bound by two or more collective agreements and it appears that the description of the bargaining unit in one of such agreements conflicts with the description of the bargaining unit in another of such agreements, the Board may, upon the application of the employer or any of the trade unions concerned, alter the description of the bargaining units in any such agreement as it deems proper, and the agreement or agreements shall be deemed to have been altered accordingly.

89(4)Before disposing of an application under this section, the Board may make such inquiry, require the production of such evidence and the doing of such things, or hold such representation votes, as it deems appropriate.