Ismail Qasim Yar, chairman of the loya jirga, invited Karzai to address the 1,650 delegates Monday after the assembly erupted in argument and accusations over what kind of legislature should represent a fragmented population.
Delegates tasked with establishing a legislature to work with Karzai are trying to decide between an assembly based entirely on geography and one based on population.
The issue is controversial because some ethnic groups, notably the Pashtuns, fear a loss of power if the new assembly is based entirely on geography. Squabbling over the issue prevented any decision from being made Sunday.
Pashtuns are the largest ethnic group, and most observers doubt the new government can rule effectively without the support of the Pashtun community, which formed the majority of Taliban ranks.
Many Pashtuns felt marginalized by the outgoing interim administration, which was dominated by ethnic Tajiks — the core of the anti-Taliban northern alliance.
"This whole process of appointing a parliament is a mess. No one has any control," Mohammed Hashim, a Pashtun delegate from Paktia province in eastern Afghanistan, said Sunday.
"If the grand council leadership says, `We have appointed our own parliament,' then all of this loya jirga — even the election of Karzai — will mean nothing. It will be illegitimate," he said.
The loya jirga, based on Afghan tradition, was convened Tuesday under a U.N.-guided blueprint to chart the country's immediate future. It drew hundreds of Afghan delegates from around the country and abroad in a two-step selection process that critics said was rife with intimidation and harassment.
Held under a vast white tent, the loya jirga has managed to accomplish only one major task — choosing Karzai as president, which it did Thursday night.
Still unresolved are the shape of the Cabinet and the form of legislature — a task the loya jirga is technically not required to undertake under the agreement struck in Germany in December that dictates the grand council's mandate.
On Sunday, initial attempts to resolve the legislature question degenerated into shouting and finger-pointing after Qasim Yar offered delegates a choice of ways to select it — either two representatives for each of 32 provinces, the initial idea endorsed by the loya jirga commission, or one for every 10 delegates.
But confusion over Qasim Yar's instructions — some of it due to language problems — produced hours of chaos. Pashtuns complained they did not understand the chairman, who spoke in Dari.
Late in the afternoon, Qasim Yar adjourned the session for the day and said Karzai would attend Monday's session to discuss options. "It's a matter of national importance and we need a national consensus," he said.
The loya jirga is supposed to conclude Monday, but with key issues unresolved, the foreign minister, Dr. Abdullah, suggested it might be extended two more days.
Many in the tent — mostly ethnic Pashtuns, who claim to compose 65 percent of the country's population — said choosing one assembly delegate for every 10 loya jirga delegates would render them voiceless in the legislative branch of a new government.
The makeup of the legislature and Cabinet will demonstrate how much power Karzai's new mandate has given him. Many of his fellow Pashtuns felt his authority in the interim administration was limited because Tajiks held key posts of defense, interior and foreign affairs.
In other developments: