Section 64(1)(b) of the Labour Relations Act requires only that written notice be given to the employer at least 48 hours before commencement of a strike, stating when the strike will commence. It does not require every employee intending to strike to give individual notice personally or through a representative, nor does it require the notice to specify the number or identity of employees who will participate. Where a trade union represents employees (including non-members) in collective bargaining and conciliation under section 64(1)(a), a single strike notice by that union is sufficient to protect the participation of all employees it represents in the strike. The right to strike under section 23(2)(c) of the Constitution is conferred without express limitation and should not be unduly restricted by reading implied requirements into the Act's provisions. Procedural pre-conditions for strike action must be interpreted in a manner least restrictive of the constitutional right to strike if the text is reasonably capable of bearing that meaning. The purpose of the strike notice is to warn the employer of impending strike action and when it will commence, not to provide full disclosure of all employees who may participate. Where employees were represented by a union in negotiations and conciliation referral, that union is competent to give the single notice required under section 64(1)(b) on behalf of all those employees.