BAGHDAD -- Iraq's parliament yesterday convened for the first time since the holidays and picked up where it left off: fighting over the resignation of its volatile speaker, Mahmoud al-Mashhadani.

The latest disagreement over who should replace Mr. Mashhadani prompted four more Sunni parliament members to pull out of the main Sunni bloc, Tawafiq, deepening the divide among the already-splintered Sunni groups. The defection comes just a couple weeks after five Sunni members from Mr. Mashhadani's party, the National Dialogue Council, withdrew.

"Tawafiq is controlled by the Iraqi Islamic Party -- all the positions, everything," said Khalaf Alayan, a National Dialogue Council member. "Every other entity within Tawafiq is marginalized. We consider it as a dissolved front."

Iraq's Sunnis widely boycotted the elections that chose the current parliament and thus are already underrepresented. The Sunni lawmakers have been unable to unify and continue to break into factions, underscoring the tenuous political landscape in Iraq.

Parliament members had already negotiated a deal requiring the new speaker to come from Tawafiq, but several Sunni Arabs said the process needs to be more open. Yesterday, Tawafiq proposed Ayad al-Sammaraie, a member of the Iraqi Islamic Party, as the new speaker, but that choice only bolstered criticism among the other Sunni parliamentarians.

Taha Luhaibi, a member of the Independent Democratic Gathering, which withdrew from Tawafiq over the weekend, said Sunni lawmakers met late into the night to discuss an alternative that will allow each Sunni party to submit its own candidate. Mr. Luhaibi will be his party's nominee for speaker.

The National Dialogue Council will propose that Mr. Mashhadani, who resigned Dec. 23, be returned to his post. The National Dialogue Front will nominate Saleh Mutlak. Other Sunni factions have yet to publicly announce their choices, Luhaibi said.

Tawafiq officials defended their choice of Mr. Sammaraie and said they remain a strong, viable coalition. Unlike his predecessor, Mr. Sammaraie is known for his calm demeanor during crises, and consistently uses reason when negotiating with others, said Nourideen Hyali of the Iraqi Islamic Party.

Mr. Hyali dismissed suggestions that Tawafiq's influence might be shrinking as parliament members continue to withdraw. In 2006, Tawafiq had 44 members from three Sunni groups.

After yesterday's defections, its numbers dropped to 32, Mr. Hyali said, though Mr. Luhaibi put the bloc's numbers as low as 27. There are 275 seats in parliament.