"146. (1) An employee has the right not to be subjected to any detriment as an individual by any act, or any deliberate failure to act, by his employer if the act or failure takes place for the purpose of - (a) preventing or deterring him from being or seeking to become a member of an independent trade union, or penalising him for doing so, (b) preventing or deterring him from taking part in the activities of an independent trade union at an appropriate time, or penalising him for doing so, or (c) compelling him to be or become a member of any trade union or of a particular trade union or of one of a number of particular trade unions."
"148. (1) On a complaint under section 146 it shall be for the employer to show the purpose for which he acted or failed to act."