The attack came less than three months after a suicide bomber killed 12 people in a blast outside a district and sessions court building in Islamabad.
It also aims to reduce the powers of the Supreme Court, with some authorities shifted to the proposed Constitutional Court, and immunity to the president from criminal proceedings for life.
A senior Pakistani Shia leader was shot dead in Lahore on Monday prompting several members of the minority sect to hold a sit-in outside the Punjab Governor's house to protest against the brutal murder.
The result is a big blow to the military establishment, revealing the limits of 'political engineering'. It reflected the anger of the electorate, especially its younger voters, who have spoken decisively against the persistent harassment and victimisation of Imran Khan's political party, asserts Rana Banerji, who headed the Pakistan desk at RA&W.