(1) Where a secret ballot has been held in accordance with the rules of a trade union as provided for in section 14, the outcome of which or, in the case of an aggregation of ballots, the outcome of the aggregated ballots, favours a strike or other industrial action and the trade union before engaging in the strike or other industrial action gives notice of not less than one week to the employer concerned of its intention to do so, that employer shall not be entitled to apply to any court for an injunction restraining the strike or other industrial action unless notice of the application has been given to the trade union and its members who are party to the trade dispute.