The new government is led by Iraq's former deputy prime minister Barham Saleh and features 20 other ministers, making the administration half the size of the previous government's 42-strong cabinet, a Kurdish parliamentary source said.

Only four ministers from the previous government retain their portfolios -- natural resources, interior, finance, and the ministry charged with the region's peshmerga guerilla force -- despite the same two parties winning elections in July, albeit by a smaller margin.

For the first time in the region's history, politics is not solely dominated by the Kurdistan Democratic Party of recently re-elected regional president Massud Barzani, and the Patriotic Union of Kurdistan of Iraqi President Jalal Talabani.

In July's polls, the Goran ("Change" in Kurdish) bloc became Kurdistan's first credible opposition movement with 25 MPs in the 111-seat assembly.

Along with 10 members of a joint Islamist-Communist bloc, Goran walked out of the session.

"We decided to walk out because the parliamentary speaker did not allow us to question Barham Saleh," said Goran MP Abdullah Mollah Nuri. "We have many reservations about how he led the (Kurdish) government in 2001 and 2004."

A parliamentary source, speaking on condition of anonymity, said: "The opposition wanted a separate vote for each ministry and it was blocked."