s 17 Contract of service not to restrict rights of employees to join, participate in or organise trade unions
17. Subject to any other written law for the time being in force, nothing in any contract of service restricts, in any way, the right of any employee who is a party to such contract —(a) to join a registered trade union; (b) to participate in the activities of a registered trade union, whether as an officer of the trade union or otherwise; or (c) to associate with any other persons for the purpose of organising a trade union in accordance with the provisions of the Trade Unions Act 1940.