The move could bring the Shiite bloc closer to resolving a nearly two-month impasse and speed the formation of a new government.

But Dr Jaafari (left) remained unwilling to resign, despite officials in his party discussing the option.

To allow more time for negotiations, the acting Speaker of Parliament, Adnan Pachachi, cancelled a meeting of the 275-member assembly scheduled for last night.

In recent weeks, rival factions within the Shiite bloc, which holds 130 seats, have jockeyed for the prime ministerial post. The bloc, the largest in Parliament, has the right to make a nomination. Dr Jaafari, considered by many to be an ineffectual leader, won the nomination in February by a single vote. He is backed by the anti-American cleric Muqtada al-Sadr.