Two-week-old talks among the 502 delegates to the Loya Jirga, or grand council, are snagged on a dispute over the power of the future presidency under the charter, which is supposed to lead to elections in mid-2004.
President Hamid Karzai and US officials are hoping a government-presented draft, awarding sweeping powers to the country's chief executive in a so-called liberal Islamic state, will be accepted.
But they face deepening opposition from powerful leaders of the armed factions who fought the Soviet occupation in the 1980s under the banner of Islam and still hold sway in the provinces.
Council spokeswoman Safia Saddiqi said on Saturday eight of the draft's 160 articles were hotly contested in a secretive committee drawing up possible amendments.
Over 500 representatives have
debated the draft for two weeks
Ashmat Ghani, a member of the so-called reconciliation committee and brother of the country's finance minister, said there was a solid majority for a presidential system.
But he said Abd al-Rasul Sayyaf, a deeply conservative Islamist, was "trying to put the word Islam into every article."
Karzai may concede control of the supreme court to conservatives in order to win their backing, opening the door to restrictions on the rights of women and religious minorities.
"There are people here with their own agendas, who want this either to work not all or to work in a way that gives them a position," Ghani told the Associated Press.
He said there were also calls for a ban on alcohol, for foreigners as well as Muslims.
Northern Alliance opposition
The draft is also under attack from representatives of the Northern Alliance faction, which helped US forces drive out the Taliban two years ago.
The position of women in the new
Afghanistan is under scrutiny
Hafiz Mansur, a delegate from the alliance who accuses Karzai of seeking dictator-style powers, said there were two dozen points on which rebel delegates wanted to force a vote.
"The government wants to impose their ideas and their draft," Mansur said. "Behind this draft is America and the United Nations. Even if you don't want it, it is imposed on you."
Mansur and several Northern Alliance leaders have called for a parliament strong enough to call the president to account.
But Karzai and US Ambassador Zalmay Khalilzad have warned of an unworkable confusion of parliamentary and presidential systems.
Afghans remember with horror how presidents and prime ministers fought each other during the 1992-96 civil war which paved the way for the arrival of the Taliban.
Still, Ghani conceded there was broad support at the council for bolstering parliament, and said one compromise might be to set up a commission to make sure the constitution is implemented fairly.