One of the smaller parties in the main Shia alliance in Iraq has said it is withdrawing from negotiations about forming a new cabinet.
Iraq's PM-designate Maliki has until 22 May to form a government
Islamic Virtue party spokesman Sabah al-Saadi said the protracted talks on the cabinet were not being conducted in a spirit of national unity.
He said the party would now form an opposition bloc in the parliament.
He also criticised what he said were external pressures from the US ambassador in Iraq.
Islamic Virtue had previously pressed for its candidates to be given the ministries of oil and trade.
"We have taken this decision because the mentality of the negotiations is dominated by personal interests and they have forgotten the main goal is to serve the Iraqi people," Mr Saadi said.
On Tuesday, Iraq's Prime Minister-designate Nouri Maliki said he had nearly completed the task of forming a new government of national unity. He said that he hoped to announce a new cabinet within two days.
However, there has been little indication of progress.
He said nominations for the key posts in the cabinet had been submitted by Shia, Sunni and Kurdish groups.
They included the defence, interior, oil, finance and foreign ministries.
Under the constitution Mr Maliki has until 22 May to finish the task. His cabinet list has to go before the Iraqi parliament for approval.
Also on Friday, Iraqi forces were reported to have clashed with insurgents in the town of Dhuluiya, north of Baghdad.
Four soldiers are said to have been killed and seven civilians injured.
It's not clear if there were any casualties among the insurgents.
In another development, the bodies of four unidentified people were found near the town of Baquba: two of them had been beheaded.
Earlier on Friday, the US military in Iraq said four of its soldiers had drowned after their tank rolled off a bridge into a canal.
The incident happened near the village of Karmah in Anbar province, west of Baghdad.
There has been heavy fighting in the province between insurgents and US forces, but the Americans said the incident was not the result of hostile action.
More than 2,400 US servicemen have died in Iraq.