The verdict affected three federal ministers belonging to the ruling Pakistan People's Party and an ally – Finance Minister Abdul Hafeez Sheikh and Petroleum Minister Asim Hussain (both members of the Senate or upper house of parliament) and Minister for Narcotics Control Khuda Bux Rajar (a member of the National Assembly or lower house of parliament).
A four-judge bench led by Chief Justice Iftikhar Chaudhry issued the order while hearing a petition filed by Pakistan Tehrik-e-Insaf chief Imran Khan, who had asked the court to declare as invalid by-polls that were held with electoral rolls containing bogus voters.
During the hearing of the petition, it emerged that 28 by-elections to parliament and provincial assemblies were held under an Election Commission that was incomplete due to non-appointment of some members.
The court gave the government time till February 6 to give legal cover to these by-polls.
The government introduced the 20th constitutional amendment in parliament to legitimise the by-polls but it could not be passed due to differences with opposition parties. The government is engaged in hectic consultations with opposition parties, particularly the PML-N, to pass the amendment.
In its order, the apex court said the 28 members of parliament and provincial assemblies will remain suspended until the 20th constitutional amendment is passed to legitimise their election.
Among the lawmakers who were suspended were nine members of the National Assembly, three Senators, 11 members of the assemblies of Balochistan, Punjab, Khyber-Pakhtunkhwa and Sindh provinces and five members of reserved seats in the various assemblies.
The apex court further directed the Election Commission to ensure that by-polls scheduled for February 25 are held with verified voters' lists.
It adjourned the matter till February 21.
The apex court has also been pressuring the government to revive corruption cases against President Asif Ali Zardari since it struck down a graft amnesty in December 2009.
A seven-judge bench has summoned Prime Minister Yousuf Raza Gilani on February 13 for the framing of contempt of court charges for refusing to reopen the graft cases.