A National Assembly session held on Monday concluded without members of the house agreeing to pass a crucial constitutional amendment bill seeking the reallocation of seats of the national and provincial assemblies and the fresh delimitation of constituencies on the basis of the provisional results of the census conducted earlier this year.

The apparent reason for the failure of the bill to pass was a lack of numbers, as the bill, which is a constitutional amendment, requires assent from two-thirds of lawmakers (228 in the 342-member house).

A visibly displeased Speaker National Assembly Ayaz Sadiq warned that if the lawmakers failed to pass the amendment soon, the Election Commission of Pakistan (ECP) will have to seek the Supreme Court's (SC) assistance in this regard.

On this, opposition leader Khursheed Shah responded that the ECP had every right to take the matter to the apex court. He, however, insisted that the 2018 general elections must take place according to the proposed schedule.

The lower house had been unable to pass the amendment in its session last week as well.

Commenting on the lack of attendance of lawmakers, Sadiq asked if he should put off parliament's proceedings for an indefinite period.

"It seems that the amendment is being deliberately delayed... [as it will lead to] an increase in the representation of smaller provinces," he remarked.

He expressed surprise at the lack of consensus, saying that the parliamentary leaders had agreed to increase the number of legislative seats during a meeting held last week. It seems, Sadiq said, that another meeting will have to be called for further consultations.

The PPP's Naveed Qamar said that his party had no objections regarding the proposed amendment; however, no matter what steps the NA speaker takes to make MNAs reach a consensus, the issue can only be resolved through dialogue.

Pakistan Tehreek-i-Insaf's Shireen Mazari declared that the absence of lawmakers when the parliament has to pass an important amendment reflects a lack of confidence. She insisted that the Assembly must resolve the reservations of all political parties.

Former prime minister Zafarullah Khan Jamali said that parliament will not be able to function properly if members take too long to pass an amendment. He also criticised the procedure of delimitation and claimed that the matter was not taken seriously.

"In order to save face, we need to resolve this matter in a transparent manner," he maintained.

The NA Speaker has summoned a meeting of the parliamentary leaders at 11am on Tuesday.