By Jim Muir
BBC News, Baghdad
Iraqi Justice Minister Hashem al-Shibli has resigned, the first cabinet member to do so since the current government took office nearly a year ago.
Shibli: 'Problems with government and party'
Mr Shibli said he had disagreements both with the government and with his own party, but no further explanation has been made public.
Mr Shibli's resignation seems to have been a pre-emptive move.
It has been known for some time that Prime Minister Nouri Maliki has been planning a cabinet reshuffle.
The justice minister's name was on the list of those he wanted to change.
The faction which had sponsored him, the Iraqi List, headed by former Prime Minister Ayad Allawi, had already been approached to suggest a replacement and it has put forward three other names.
Mr Shibli clearly preferred to walk before being pushed.
Without elaborating, he said he had had problems both with the government and with his own party.
Political sources suggested that one of his issues with the government had been over the manner in which Saddam Hussein was hanged at the end of December.
As justice minister, Mr Shibli, who is a Sunni Arab, believed the death sentence should have gone to the Iraqi presidency for approval, a step which was skipped.
As for his differences with the Iraqi List, they seem to have been over the issue of Kirkuk, the oil-rich province which the Kurds would like to see join the three others currently making up Iraqi Kurdistan, an autonomous federal region.
Arrangements for determining Kirkuk's future are contained in Article 140 of the new Iraqi constitution.
Mr Shibli was head of the commission in charge of implementing that article.
It made recommendations for proceeding which were endorsed by the cabinet on Thursday.
But the Iraqi List is against the Kirkuk process, putting Mr Shibli in a contradictory position.