Circumstances in which parties are treated as complying with the grievance procedures
10. Where either of the grievance procedures is the applicable statutory procedure but—
(a)at the time the employee raises his grievance there is a procedure in operation, under a collective agreement made between two or more employers or an employers' association and one or more independent trade unions, that provides for employees of the employer to raise grievances about the behaviour of the employer and have them considered, and
(b)the employee is entitled to raise his grievance under that procedure and does so,
the parties shall be treated as having complied with the applicable statutory procedure.