20.—(1) Where, within 7 days after service of a notice under section 18, a trade union or employer upon whom it was served has not served an acceptance under section 19, the employer or trade union by whom the notice was served may notify the Commissioner.
(2) Upon receipt of a notification under subsection (1), the Commissioner shall consult, or direct a conciliation officer to consult, with the employer or trade union which has not served an acceptance with a view to persuading that employer or trade union to accept the invitation.
(3) Where, after consultation with an employer or trade union on whom an invitation to negotiate has been served, the Commissioner is satisfied that the employer or trade union refuses to negotiate, he shall notify the Minister and, unless the Minister otherwise directs, the Registrar that a trade dispute exists.