Section 33(3) in The Industrial Disputes Act, 1947
(3)Notwithstanding anything contained in sub-section (2), no employer shall, during the pendency of any such proceeding in respect of an industrial dispute, take any action against any protected workman concerned in such dispute-(a)by altering, to the prejudice of such protected workman, the conditions of service applicable to him immediately before the commencement of such proceedings; or(b)by discharging or punishing, whether by dismissal or otherwise, such protected workman, save with the express permission in writing of the authority before which the proceeding is pending.Explanation .-For the purposes of this sub-section, a "protected workman ", in relation to an establishment, means a workman who, being ] [a member of the executive or other office bearer] [ Substituted by Act 45 of 1971, Section 5, for " an officer" (w.e.f. 10.3.1957).][of a registered trade union connected with the establishment, is recognised as such in accordance with rules made in this behalf.