Sunday, 500 of Afghanistan's most prominent citizens gather to adopt a new constitution and decide the nation's next form of government.

The constitutional grand council, the "loya jirga", meeting this month will determine how Afghanistan is governed. The transitional administration has been in power two years, since the overthrow of the hardline Islamist Taleban regime by U.S.-led forces.

Delegates representing all 32 provinces and special groups - such as women, scholars and nomads - will gather under a massive traditional white tent on the edge of the capital.

The delegates also include 50 members chosen by interim President Hamid Karzai, but there will be no one from his government.

The debate is expected to focus on whether to concentrate power in the hands of a president or to have a parliament that spreads power among Afghanistan's various political and ethnic groups.

Farooq Wardak, who heads the constitutional secretariat, believes consensus-building is what Afghanistan's traditional loya jirga system is all about.

"If they cannot bring agreement, who else can bring agreement? ? I am confident there will be agreement at the end," he said.

The council will begin with a plenary session of all delegates - who will elect a chairperson and then divide into committees to discuss various aspects of the constitution.

But a shadow of insecurity hangs over the loya jirga, as remnants of the Taleban regime and other elements opposed to the constitutional process have threatened violence.

Lieutenant Colonel Bryan Hilferty is spokesman for U.S. military forces fighting Taleban insurgents inside Afghanistan.

"The Taleban have made public proclamations that they want to disrupt the loya jirga. They would like to kill the delegates," he said.

In an effort to stem possible attacks on the gathering, Afghan and international forces are patrolling in and around Kabul around the clock.

The loya jirga is scheduled to last 10 days, but can be extended if the delegates chose to do so.