Pakistan ran under the remnant of Martial Law LFO (Legal Framework Order) without any proper constitution. It was obligatory on the Legislature to frame a new constitution for a country, so it appointed a 25-member Constitutional committee composed of all the political parties represented in the parliament according to their strength on 17 April 1972, to prepare a draft of the permanent Constitution of Pakistan.
Khan Amirzadah Khan and
Mir Ghous Bux Bizenjo were representing
National Awami Party. This Constitutional Committee headed
Abdul Hafiz Pirzada of
Pakistan Peoples Party work day and night for many months and framed a draft constitution which was presented in the parliament and adopted as the well-known 1973 constitution. Khan Amirzadah Khan deliberated and delivered his famous speech of 5 hours and 35 minutes on this constitution, this speech is still holding the record of the longest extempore speech of the
National Assembly of Pakistan. According to this constitution, no person could hold membership of more than 1 Assembly at a time. Hence,
Khan Abdul Wali Khan resigned from the membership of NWFP assembly and retained the seat of National Assembly of Pakistan. On the advice of the party leadership, Khan Amirzadah Khan resigned from the National Assembly and retained the membership of NWFP assembly seat. Where Khan Amirzadah Khan was elected as leader of the opposition, which he retained till the end of the tenure of the assembly.
Dismissal of NAP government and arrest In 1973, the
Bhutto regime citing
Nawab Akbar Bugti's claim that the NAP Leaders were trying to disintegrate Pakistan as a basis, dismissed the NAP Government. Mir Ghaus Bakhsh resigned in protest. Mir Gul Khan Nasir and Sardar Abdul Rehman were arrested. A few days later Ghaus Bakhsh Bizenjo,
Ataullah Mengal,
Khair Bakhsh Marri, Mir Ghaus Bakhsh's son Bizen and Colonel (R)
Sultan Mohammad Khan (the head of Balochistan Reserve Police) were arrested. They spent more than four years in jail.
Hyderabad tribunal Later, a commission known as Hyderabad tribunal, was set up and Mir Ghaus Bakhsh Bizenjo,
Sardar Ataullah Mengal, Mir Gul Khan Nasir,
Khair Bakhsh Marri,
Khan Abdul Wali Khan,
Khan Amirzadah Khan, Syed Muhammad Kaswar Gardezi,
Habib Jalib and many others had to defend themselves in a treason case in front of the tribunal. After the ouster of
Zulfiqar Ali Bhutto's government by General
Muhammad Zia-ul-Haq, negotiations for the winding up of the
Hyderabad tribunal and the release of all detainees was initiated leading to their eventual release in 1979. == NDP and PNP parties ==