Article 273: First Provincial Assembly
1. Notwithstanding anything contained in the Constitution, but subject to Article 63, Article 64 and Article 223,-
a. the first Assembly of a Province under the Constitution shall consist of
i. the members of the Assembly of that Province in existence immediately before the commencing day, and
ii. the additional members to be elected in accordance with law by the members of the Assembly to fill the seats referred to in clause (3) of Article 106, and, unless sooner dissolved, shall continue until the fourteenth day of August, one thousand nine hundred and seventy-seven; and reference to "total membership" of the Assembly of a Province in the Constitution shall be construed accordingly;
b. the qualifications and disqualifications for membership of the first Assembly of a Province shall, except in case of members filling casual vacancies, or to be elected to the additional seats referred to in clause (3) of Article 106, after the commencing day, be the same as were provided in the Interim Constitution of the Islamic Republic of Pakistan:
Provided that no person holding an office of profit in the service of Pakistan shall continue to be a member of the Assembly after the expiration of three months from the commencing day.
2. A casual vacancy in a seat in the first Assembly of a Province, including a vacancy in a seat in the Assembly of that Province in existence immediately before the commencing day which was not filled before that day, caused by reason of death or resignation of a member or consequent upon his incurring a disqualification or ceasing to be a member as a result of the final decision of an election petition may be filled in the same manner in which it would have been filled before the commencing day.
3. A member referred to in paragraph (a) of clause (1) shall not sit or vote in the Provincial Assembly until he has made the oath prescribed by Article 65 read with Article 127 and, if, without leave of the Speaker of the Provincial Assembly granted on reasonable cause shown, he fails to make the oath within twenty-one days from the day of the first meeting of the Provincial Assembly, his seat shall become vacant at the expiration of that period.