90(1)
Where an industrial dispute pertaining to an establishment or undertaking is already pending before a conciliation officer or an Arbitrator or a Tribunal or a National Industrial Tribunal, as the case may be, with regard to matters not covered by the notice of change issued by an employer under section 40, no employer shall—
90(1)(a) in regard to any matter connected with such dispute, alter to the prejudice of the workers concerned in such dispute the conditions of service applicable to them immediately before the commencement of such proceedings; or
90(1)(b) for any misconduct connected with the dispute, discharge or punish, whether by dismissal or otherwise any worker concerned in such dispute, save with the express permission in writing of the authority before which the proceeding is pending.