Iraqi Prime Minister Nouri Maliki has not unveiled his new cabinet, which was expected on Monday, amid ongoing disputes among Iraq's rival factions.
It is the latest setback in efforts to form a unity government in Iraq, nine months after parliamentary elections.
Up to half the ministerial posts were undecided, as party leaders wrangled over allocations, officials said.
It is not clear when parliament will vote on the cabinet list, but the constitutional deadline is Saturday.
There are 37 posts in all, and dividing up portfolios among Iraq's diverse and often mutually antagonistic factions has been the focus of the past month's political wrangling.
Mr Maliki had been expected on Monday to name his entire cabinet, except for three sensitive posts linked to national security, but parliament was adjourned without receiving any list.
The new cabinet is expected to include all the major factions, including the Kurds, Shia and Sunni Arabs.
The speaker of parliament, Osama al-Nujaifi, said a vote could come as soon as Tuesday.
But other lawmakers have vowed to reject any vote on a partial list, saying they will wait until the full cabinet is finalised and the horse-trading over.
It will be a delicate balancing act for Mr Maliki, who has to reconcile various Shia groups, as well as the Sunnis and the Kurds, to put together government of national unity that has at least a chance of being able to work together, says the BBC's Gabriel Gatehouse in Baghdad.
But the real test of this coalition will come when these newly-appointed ministers get down to work, and start to tackle the country's many problems - from neglected and crumbling infrastructure to continuing violence and instability, our correspondent says.