14. (1) Any member of the Council may at any time resign his membership by writing under his hand addressed to the President and the seat of such member shall become vacant when such resignation is notified in the Gazette. (2) A member of the Council shall be deemed to have vacated his seat if he is declared by the Council to have been absent without sufficient excuse from three consecutive meetings of the Council, or if his name is, for any cause, removed from the Register under the provisions of Article 20. (3) A casual vacancy in the Council shall be filled by fresh election from the constituency concerned or by nomination by the Government, as the case may be, and the person elected or nominated to fill the vacancy shall hold office until the dissolution of the Council: Provided that no election shall be held to fill a casual vacancy occurring within six months prior to the date of the expiry of the duration of the Council, but such a vacancy may be filled by co-option by the Council. (4) No act done by the Council shall be called in question on the ground merely of the existence of any vacancy in, or defect in the constitution of, the Council.