Some members of the coalition parties have reportedly questioned the "hasty" way the debate was scheduled, saying it was aimed to pressure other parties in the coalition government to accept the nomination.

The PPP reportedly moved up the voting from earlier scheduled Wednesday to Monday.

The search for the new House Speaker has been closely watched as the PPP-led coalition government and its opponents are engaged in a battle over the amendments to the 2007 Constitution, which was installed by the military-backed interim government after a military coup on Sept. 19, 2006 toppled Thaksin Shinawatra administration and abrogated the 1997 Constitution.

The PPP, the reincarnation of the Thaksin-founded TRT, has been pushing for the charter amending since it won the Dec. 23 election and formed the current coalition government.

The Democrat has accused Monday's debate was part of the government's scheme to push through its plan to amend the constitution.

Chai will fill the vacancy left by Yongyuth Tiyapairat, a former deputy leader of PPP who is facing trial for electoral fraud charges in last December's general election and resigned from his post as House Speaker and Parliament President on April 30.

On Monday, the Supreme Court's Criminal Division for Holders of Political Positions will summon former House Speaker Yongyuth to testify in the election fraud case against him.

Yongyuth had denied the vote-buying charges and said he resigned to uphold the dignity of the institution and to fight his case in the Supreme Court after the Election Commission sought to disqualify him, charging him of having bribed local heads in his hometown in the northernmost province of Chiang Rai where he contended as an PPP MP candidate to ensure his victory in the Dec. 23 election.

47-year-old Yongyuth was elected as the House Speaker and President of Parliament on Jan. 22, after the PPP declared victory in the Dec. 23 election.

(Xinhua News Agency May 12, 2008)