In section 57(3) of the 1978 Act (determination of question of fairness to depend on whether employer can satisfy tribunal that he acted reasonably) for the words from “the employer can” to the end there shall be substituted the words “ in the circumstances (including the size and administrative resources of the employer’s undertaking) the employer acted reasonably or unreasinably in treating it as a sufficient reason for dismissing the employee ; and that question shall be determined in accordance with equity and the susbtantial merits of the case ”.