UNITED NATIONS, May 1: The United Nations special envoy Lakhdar Brahimi will leave for Baghdad on Sunday to help set up a new government, hopefully by the end of May, UN officials here said.

The officials and diplomats here said that Shia leaders are the leading candidates for the top posts of president and the prime minister in the new caretaker interim government being suggested by Mr Brahimi.

Mr Brahimi, asked by the US to oversee the transition to Iraqi rule, must resolve disputes among Iraqi officials over how a government should be chosen and opposition by some to UN or US control of the process. However, the new turmoil in Iraq threatens to complicate American plans for the handover.

Officials in Mr Brahimi's office said he has not agreed on any of the dozen or so candidates that have emerged.