A scheduled session of Iraq's parliament tomorrow was postponed by the acting speaker today, further delaying the formation of a government already held up by four months of wrangling by political groups.
Adnan Pachachi made the decision after Iraq's Shia Alliance proposed a new nominee for prime minister but said it opposed the main Sunni Arab grouping's candidate for parliamentary speaker, raising a possible new crisis.
After four months of resisting Kurdish and Sunni opposition to Prime Minister Ibrahim al-Jaafari as its nominee for the top government job, the Alliance put forward Dawa party leader Ali al-Adeeb, officials in the Shia bloc said.
Although the Alliance has not officially withdrawn Mr Jaafari's name, the premiership move could end the months of political paralysis that Washington has blamed for fuelling increased sectarian violence betweeen Sunnis and the majority Shias.
But Iraqi leaders could be headed for a new impasse over Tareq al-Hashemi, whom the Sunni Iraqi Accordance Front has nominated as speaker of parliament.
Tomorrow's parliamentary session, which Mr Pachachi delayed for a "few days", had raised hopes politicians would bury differences and choose a national unity government, widely seen as the best chance of averting a sectarian civil war.
"The Alliance has floated Ali al-Adeeb as its candidate for prime minister. But if the Alliance does not drop its opposition to Mr Hashemi as parliament speaker the parliament session will be delayed," said an Alliance official, declining to be named.
Mr Adeeb is not well known in Iraq but political sources said the Alliance opted for him because, unlike other candidates, he was not considered sectarian.
New violence erupted in Iraq, showing Iraqi leaders were still unable to curb violence after national elections in December they promised would deliver stability.
Even if political obstacles are overcome, no government will have any easy solutions to a Sunni insurgency and sectarian bloodshed that have scared away foreign investors from the major oil producer's economy.
Months of wrangling have hurt the credibility of Iraqi leaders, who have struggled to keep Iraq from sliding into open civil war since the February bombing of a Shia shrine.