UN staff are expected to make an unprecedented vote of no confidence in Secretary-General Kofi Annan, union sources say, after a series of scandals tainted his term in charge of the world body.

The UN staff union, in what officials said was the first vote of its kind in the almost 60-year history of the United Nations, was set to approve a resolution withdrawing support for Annan and senior UN management.

Annan has been in the line of fire over a series of scandals including controversy about a UN aid program that investigators say allowed deposed Iraqi dictator Saddam Hussein to embezzle billions of dollars.