UN general-secretary Kofi Annan's chief adviser, Lakhdar Brahimi, will brief security council members today and is expected to suggest holding direct elections later this year or early next year. But a key section of the anticipated report, concerning what form of caretaker government should be installed, will be delayed until further consultation between Mr Annan and his advisers.

In January, the UN agreed to return to Iraq to help resolve the dispute between the US occupying force and the coun try's Shia majority over how to hand back power to Iraqis. Shia demands, backed by huge demonstrations, to hold direct elections by the end of June have been rejected as impractical by the UN. But the United States' proposals to hold 18 regional caucuses of the "great and good" to chose an interim legislature have also been rejected, forcing both sides to revise their plans.

Mr Brahimi's report is due to be presented today or tomorrow after he spent a week in Iraq at the request of the UN and the US.

Having originally dismissed the UN, the Bush administration has been forced to return to it to mediate, as the security situation continues to deteriorate. The UN, meanwhile, has been reluctant to intervene. It pulled out of the country after the blast on August 19 that destroyed its office in Baghdad, killing 22.

The Bush administration, with an eye on the presidential elections in November, has said that it plans to hand over some power to the Iraqis on July 1, but that it was flexible about how it did so and to what kind of body.

Associated Press reported late last night that a senior US official said the administration was considering extending the US-appointed governing council so it could take temporary control of the country.

The US-proposed caucus system had little support, even from the 25-member Iraqi governing council.

A state department spokesman, Richard Boucher, said yesterday that "we'll hear from the secretary-general when he is ready, when they have formulated their ideas and want to talk to us".

"Who knows what they will come up with."

• Two suicide car bombings at a military base south of Baghdad killed at least 11 Iraqis yesterday. A spokesman at the Polish-commanded logistics base at Hilla said the attacks left 102 people injured, 58 of them foreign soldiers.