The UN secretary general, Kofi Annan, emerged from a meeting with US, British and Iraqi officials, promising to consider an appeal for UN experts to visit Iraq to assess how best to achieve the June 30 power transfer.

Paul Bremer, the top US official in Iraq, is hoping that any UN experts sent to Iraq will agree with the American view on the power handover: that direct elections are impossible in the circumstances, and that an interim government will have to be selected through nomination and selection rather than election.

Mr Annan has hinted that he agrees. "I don't believe there may be enough time between now and May to hold elections," he said yesterday. He added that more talks would be needed before he could reach a decision on whether to send experts back to Baghdad, scene of a devastating attack on UN personnel in August last year.

But he suggested it would be unwise to refuse the request, and his decision will not be long in coming as preparations for the power transfer start next month.

"If we get it wrong at this stage, it'll be even more difficult and we may not even get to the next stage," Mr Annan said. "So I think it is extremely important that we do whatever we can to assist."

Iraq's majority Shia population is calling for rapid general elections to be held. Their most influential cleric, Ayatollah Ali Sistani, has warned that failure to hold a vote will only aggravate violence.

Yesterday, around 100,000 Shia Muslims took to the streets of Baghdad demanding early and direct elections.

"The sons of the Iraqi people demand a political system based on direct elections and a constitution that realises justice and equality for everyone," said Ayatollah Sistani's representative, Hashem al-Awad. "Anything other than that will prompt people to have their own say."

"We are demanding democracy," said a cleric, Faras al-Tatrasani. "And that's what America came to give us."

Ayatollah Sistani has indicated he would accept the UN team's decision, even if it affirms Mr Annan's belief that direct elections are unfeasible.

But the UN is also wary about validating a process it has no role in formulating and submitting itself to a timetable dictated by President George Bush's desire for re-election.

"Nobody can afford to see Iraq implode," said one UN official. "But we want to keep the interests of the Iraqi people at the centre of what we do, and we have to be careful in which way we go from here."

Security meanwhile remains paramount in Mr Annan's mind, particularly following the August 19 blast that levelled a UN office in Baghdad, killing 22.