The Provisional Constitutional Order (PCO) is an emergency and extra-constitutional order that suspends either wholly or partially the Constitution of Pakistan — the supreme law of the land.^[1]

The PCO acts as a temporary order while the constitution is held in abeyance or suspension.^[2] These orders have mostly been enforced during times of martial law imposed by the armed forces of the country against the civilian governments.^[1]

Soon after the martial law went into effect in 1977, the Constitution of Pakistan was suspended. The first Provisional Constitutional Order (PCO) was declared on March 24, 1981, by then-President and Chief of Army Staff General Muhammad Zia-ul-Haq.^[3]

Under this new order, the senior justices of the Supreme Court of Pakistan were asked to take an oath of office under the provisions set by the PCO.^[3] In March 1981, President Zia terminated 19 senior justices of the Supreme Court when they refused to take the oath.^[4] Chief Justice Dorab Patel and Senior Justice Fakhruddin G. Ebrahim declined to take the oath, thus opting for retirement.^[4] Senior Justice Sheikh Anwarul Haq also resigned after refusing to take the oath, while Senior Justice Maulvi Mushtaq Hussain, who was willing to take the oath, was not asked to do so.^[4]

Senior Justices Hussain and Haq had previously approved Zulfikar Ali Bhutto's hanging and were reportedly restrained from taking the oath under the secretive directives issued by President Zia.^[4] All of these senior justices were asked to tender their resignation, which they did.^[4]

In the wake of political tensions arising after the border incidents with India that nearly pushed the two countries to the brink of war, Chairman Joint Chiefs of Staff Committee and Chief of Army Staff General Pervez Musharraf imposed martial law against the government of Prime Minister Nawaz Sharif on October 12, 1999.

General Musharraf effectively imposed a state of emergency and suspended the Constitution after introducing the Provisional Order. Nearly all senior justices were required to take an oath of office under this new order, and concerns were raised that this would "erode the independence of the judiciary".^[5]

In 2007, another Provisional Constitutional Order (PCO) was issued by General Pervez Musharraf. The PCO was issued on November 3, 2007, and was later amended on November 15, 2007. It was lifted on December 16, 2007.