Hussein al-Shahristani, the oil minister, was quoted by the state-run al-Sabaah newspaper as saying: “The ministry isn’t committed to oil investment contracts signed in the past . . . by officials of the government of the Kurdistan region which were announced as contracts for investment and the development of oil fields.”

The Kurds have signed production-sharing agreements in the past year allowing several international companies, including Norwegian and Turkish groups, to begin drilling in the north, and the KRG’s oil minister Ashti Hawrami said last week that more contracts will be signed in October.

Baghdad, however, has consistently insisted that only the federal government has the right to make such deals. Both sides say they are discussing the issue as part of negotiations over a federal hydrocarbons law, to be passed either by the end of this year or at the beginning of the next.

The latest dispute comes as Iraq’s parliamentarians on Sunday agreed to begin debate on the issue of federalism, but said they would delay the creation of any new autonomous areas for at least 18 months.

Politicians said that the first reading of a controversial bill on the creation of autonomous regions would take place on Tuesday, ending a deadlock that has polarised parliament since it reconvened earlier this month.

Some Shia groups such as the Supreme Council for Islamic Revolution in Iraq favour the adoption of a law that would allow them to create a federal region in oil-rich southern Iraq similar to the existing Kurdistan Regional Government in the north.

New federal regions, however, are opposed by other Shia, as well as by most Sunnis who fear that it will leave their oil-poor heartland in the centre starved of resources.

■Saddam Hussein’s defence team will boycott his genocide trial indefinitely, citing violations by the Iraqi court trying him, his chief lawyer said on Sunday, reports AP.

“The court committed several violations of the law and we won’t just sit there gagged to give it legitimacy,” said Khalil al-Dulaimi, who is in charge of a nine-member defence team for the deposed Iraqi leader. Mr Hussein faces charges of committing genocide against Kurds in northern Iraq.