c. where the incumbent ceases to hold that office in pursuance of section 50 or 51 of this Constitution: Provided that the President shall not resign or retire from his office even at the due expiration of his term of office while a general election of Members of Parliament is pending within the ensuing three months, or where a state of public emergency has been declared. (2) If Sierra Leone is at war in which the national territory is physically involved, and the President considers that it is not practicable to hold elections, Parliament may by resolution extend the period of five years mentioned in subsection (1) of section 46, but no such extension shall exceed a period of six months at any one time. (3) Any resignation or retirement by a person from the office of President shall be in writing addressed to the Chief Justice and a copy thereof shall be sent to the Speaker and the Chief Electoral Commissioner. (4) Whenever the President dies, resigns, retires or is removed from office as a result of paragraphs (b) and (c) of subsection (1), the Vice-President shall assume office as President for the unexpired term of the President with effect from the date of the death, resignation, retirement or removal of the President, as the case may be. (5) The Vice-President shall, before assuming office as President in accordance with subsection (4), take and subscribe the oath for the due execution of his office as set out in the Second Schedule to this Constitution. Mental or physical incapacity. 50. (1) Where the Cabinet has resolved that the question of the mental or physical capacity of the President to discharge the functions conferred on him by this Constitution ought to be investigated and has informed the Speaker accordingly, the Speaker shall, in consultation with the Head of the Medical Service of Sierra Leone, appoint a Board consisting of not less than five persons selected by him from among persons registered as medical practitioners under the laws of Sierra Leone. (2) The Board appointed under subsection (1) shall enquire into the matter and make a report to the Speaker stating the opinion of the Board whether or not the President is, by reason of any infirmity of mind or body, incapable of discharging the functions conferred on the President by this Constitution. (3) Where the Cabinet has resolved that the question of the mental or physical capacity of the President to discharge the functions conferred on him by this Constitution ought to be investigated in accordance with the provisions of subsection (1), the President shall, as soon as another person assumes the office of President, cease to perform those functions and until the Board submits its report, those functions shall be exercised in accordance with subsection (1) of section 52 of this Constitution. (4) Where the Board reports that the President is incapable of discharging the functions conferred on him by this Constitution by reason of infirmity of mind or body, the Speaker shall certify in writing accordingly, and thereupon, the President shall cease to hold office and a vacancy shall be deemed to have occurred in the office of President and subsection (4) of section 49 of this Constitution shall apply. (5) Upon receipt of the report of the Board referred to in subsection (4), the Speaker shall— a. b. if Parliament is then sitting or has been summoned to meet, within five days communicate the report to Parliament; if Parliament is not then sitting (and notwithstanding that it may be prorogued), summon Parliament to meet within twenty-one days after the receipt by the Speaker of the report of the Board and communicate the report of the Board to Parliament. (6) For the purposes of this section— a. the Cabinet may act notwithstanding any vacancy in its membership or the absence of any member; 30