The center-right BNP won a plurality of seats and formed a coalition government with the Islamic party Jamaat-e-Islami Bangladesh, with Khaleda Zia, widow of Ziaur Rahman, obtaining the post of Prime Minister. Only four parties had more than 10 members elected to the 1991 Parliament: The BNP, led by Prime Minister Begum Khaleda Zia; the AL, led by Sheikh Hasina; the Jamaat-e-Islami (JI), led by Golam Azam; and the Jatiya Party (JP), led by acting chairman Mizanur Rahman Choudhury while its founder, former President Ershad, served out a prison sentence on corruption charges. The electorate approved still more changes to the constitution, formally re-creating a parliamentary system and returning governing power to the office of the prime minister, as in Bangladesh's original 1972 constitution. In October 1991, members of Parliament elected a new head of state, President Abdur Rahman Biswas.