The bill would strip the Pakistani president of his sweeping powers
Pakistan's parliament has begun debating a bill of constitutional amendments that would strip the president of his sweeping powers.
Among other measures, the draft amendment would transfer powers from the office of the president to the prime minister.
This would include taking away the president's power to dismiss an elected government and appoint military chiefs.
An all-party parliamentary committee has already agreed on the amendments.
The amendments would also rename the North West Frontier Province, Khyber Pakhtoonkhwa - meaning "Khyber side of the land of the Pakhtuns".
The renaming of the province has been a long-standing demand of the ethnic Pashtuns who dominate the region.
Constitutional amendments in Pakistan require a two-thirds majority both in the Senate and National Assembly.
But since all the major political parties have signed the draft, it is expected to sail smoothly through the two houses, says the BBC's Ilyas Khan in Islamabad.
Correspondents say the consensus on the agreement is being viewed as a major success of the country's political leadership and the amendment will strengthen democracy in the country.
The present constitution confers vast powers on the president, including the power to appoint services chiefs, the head of the election commission and the head of the public service commission.
The president also has the power to dismiss all or any of the central or provincial governments and parliaments.
President Asif Ali Zardari indicated that he would do away with these powers in March last year.
In his first annual address to the parliament, he had said he wanted a package of constitutional reforms designed to restore the 1973 constitution to its original form.