Al Jazeera’s Kamal Hyder said from Islamabad: “The bill will need a majority of two thirds in the Senate, before it is sent to the president. The signature of the president would effectively take away the president’s powers, which some of them considered to be quite draconian in nature.”
The bill is likely to spark debate in the senate, especially over the renaming of provinces.
Our correspondent said: “The debate (in the senate) is not likely to go smoothly because there are issues such as the renaming of the province [North-West Frontier], which has whipped up quite a storm here and led to street protests.”
The bill also seeks to enhance provincial autonomy, repealing the controversial 17th Amendment of 2003 that legitimised the previous president, Pervez Musharraf’s decrees.
Sovereignty of parliament
The amendments, crafted by parliamentarians from both ruling and opposition groups, will turn Zardari into a ceremonial head of state.
But analysts say he still will maintain his hold on the Pakistan People's Party (PPP) and keep Yusuf Raza Gilani, the prime minister's loyalty.
Two of the biggest privileges of past presidents - soon to be lost by Zardari - were the power to dissolve the national assembly and appoint the heads of the armed forces and judges.
Gen. Mohammad Zia-ul-Haq, a former military ruler, introduced these powers in the 1980s to maintain control over the government.
In the 1990s, the national assembly and four provincial assemblies were dissolved three times, ousting the governments of former prime ministers Benazir Bhutto and Nawaz Sharif.
A leader in the main opposition party, the Pakistan Muslim League-N - the party of Zardari's chief rival, Nawaz Sharif - urged the government to focus on resolving chronic problems, including inflation, power shortages and unemployment.
"The prime minister's responsibilities have increased," Nisar Ali Khan said.
"Now he has no excuse; this government has no excuse but to resolve people's problems.
"Today, we all have got to give a commitment that no politician, no Pakistani will support a military dictator," he said.
The military has ruled Pakistan for about half of its 63 years of independence.