(1) Parliament may by law—
(a) vary or revoke, whether prospectively or retrospectively, the conditions of services as respects remuneration, leave and pension and the rights as respects disciplinary matters of persons who, having been appointed by the Secretary of State or Secretary of State in Council to a civil service of the Crown in India before the commencement of this Constitution, continue on and after the commencement of the Constitution (Twenty-eighth Amendment) Act, 1972, to serve under the Government of India or of a State in any service or post;
(b) vary or revoke, whether prospectively or retrospectively, the conditions of service as respects pension of persons who, having been appointed by the Secretary of State or Secretary of State in Council to a civil service of the Crown in India before the commencement of this Constitution, retired or otherwise ceased to be in service at any time before the commencement of the Constitution (Twentyeighth Amendment) Act, 1972: Provided that in the case of any such person who is holding or has held the office of the Chief Justice or other Judge of the Supreme Court or a High Court, the Comptroller and Auditor-General of India, the Chairman or other member of the Union or a State Public Service Commission or the Chief Election Commissioner, nothing in sub-clause
(a) or sub-clause
(b) shall be construed as empowering Parliament to vary or revoke, after his appointment to such post, the conditions of his service to his disadvantage except in so far as such conditions of service are applicable to him by reason of his being a person appointed by the Secretary of State or Secretary of State in Council to a civil service of the Crown in India.