Baghdad, Iraq ? Under U.S. pressure, Iraqi leaders decided Wednesday to convene parliament in a bid to jump-start formation of a new unity government, stalled for months over the choice of a prime minister.

But Shiite officials raised doubts whether the session – already postponed once this week – would take place today as planned. They said the seven-faction Shiite alliance would meet this morning and decide whether to attend the afternoon session.

The Bush administration is anxious to get a broad-based government seated, hoping it will help undermine support for the insurgency as well as calm sectarian strife that has bloodied Iraq in recent months.

At least 17 people were killed Wednesday, police said, and the bodies of 10 other people were found in Baghdad and Kut – apparently the victims of reprisal killings by Shiite and Sunni extremists.

Parliament had been set to convene Monday, but the session was delayed to allow Shiite leaders time to resolve the deadlock over their nomination of Prime Minister Ibrahim al-Jaafari for a second term. Sunni and Kurdish parties oppose al-Jaafari, blaming him for the surge in sectarian violence.

But al-Jaafari insisted Wednesday that he still enjoyed the support of the Shiite alliance, the dominant bloc in parliament, and would not step aside.

“As a matter of principle, I think the idea of making a concession is, for me at least, out of the question,” he said at a nationally televised news conference.

However, Iraqi leaders are under enormous pressure from the United States and Britain to form a national unity government to stem the country’s slide toward chaos and enable Washington and London to show political progress to electorates becoming more skeptical of Iraq policy.

Shiite officials said U.S. Ambassador Zalmay Khalilzad insisted parliament convene this week in hopes of generating political momentum, Iraqi politicians said. After a series of meetings, acting speaker Adnan Pachachi announced the session for 4 p.m. today.

Lawmakers, who have met briefly only once since the Dec. 15 election, were not expected to decide on al-Jaafari but were to choose a new parliament speaker and fill other posts.