Vacation of and removal from office of President
(3) The Prime Minister or not less than one-quarter of the total number of the elected Members of Parliament referred to in Article 39(1)(a) may give notice of a motion alleging that the President is permanently incapable of discharging the functions of his office by reason of mental or physical infirmity or that the President has been guilty of —
(a) intentional violation of the Constitution;
(c) misconduct or corruption involving the abuse of the powers of his office; or
(d) any offence involving fraud, dishonesty or moral turpitude,
and setting out full particulars of the allegations made and seeking an inquiry and report thereon.
http://statutes.agc.gov.sg/aol/s ... A0;rec=0#pr22L-he-.