The current parliamentary system was adopted in 1991. Between 1975 and 1990 the nation experienced military rule. A caretaker government was first introduced in 1990 after the resignation of military dictator Lieutenant General HM Ershad to observe a neutral democratic election, as per demands of the two major political parties Bangladesh Nationalist Party (BNP) and Bangladesh Awami League. Following the forced resignation of HM Ershad, Chief Justice Shahabuddin Ahmed was nominated as the Chief Advisor and observed the 1991 general election. A Caretaker government is headed by a Chief Adviser who enjoys the same power as the regular prime minister of the country except defense matters. The Advisors function as Ministers. After 1991, the Caretaker government has also held the elections of 1996, 2001 and 2008. Although the first caretaker government was intended to help the transition from authoritarianism to democracy, this system was institutionalized in 1996 by the Sixth Parliament due to rising mistrust between the BNP and Awami League. In 2011 the then ruling party Awami League abolished the caretaker government system. This has been the biggest cause of dispute among many others between the BNP and the Awami League since then.