Bangkok  - The vote for Thailand's next premier at an extraordinary session of parliament on Monday will be very close with the outcome still far from certain, politicians predicted Sunday.

Parliament will reconvene to vote on the 27th prime minister, now a toss-up between Democrat party leader Abhisit Vejjajiva and Puea Paendin party leader Police General Pracha Promnok.

Democrats claim to have secured some 260 of the 438 seats in the Lower House, enough to win Abhisit, 44, the premiership, but the real numbers will not be known until after the vote Monday morning.

"It will be a close call," predicted Kraisak Choonhavan, a senior member of the Democrat party.

The Democrats - who have been in the opposition since former prime minister Thaksin Shinawatra and his Thai Rak Thai party romped to victory on the back of a populist platform in the January 2001 general election - claim to have won the support of four smaller political parties and a breakaway faction from the former People Power Party that led the last government.

But the coalition lineup appeared to be falling apart Sunday when Pracha, head of the Puea Paendin party that supposedly supports the Democrats, accepted a nomination to contest for the premiership.

It is unclear how many members of parliament Pracha actually controls within his own party, which holds 29 seats.

"The Puea Paendin is a hydra with many heads," said Kraidsak. "The leader actually only controls four to five people."

Pracha claimed to control at least 16 of his own MPs, which might be enough to secure him the premiership with the backing of the Puea Thai - a reincarnation of the now defunct People Power Party - and Phracharaj party of Sanoh Thiengthong.

"If he has 16 MPs, Pracha has a good chance to win the premiership," said Chaturon Chaisaeng, a former politician in the Thaksin government.

There are fears that if Pracha becomes the next prime minister, Thailand's political impasse will continue and the street protests that undermined the last government will be resumed.

The People's Alliance for Democrcay (PAD), the movement that toppled the last government by closing Bangkok's two airports for a week, has promised to return to the streets if the next government is run by a Thaksin proxy.

The last government was headed by Somchai Wongsawat, Thaksin's brother-in-law. Thaksin, a former billionaire telecommunications tycoon, was prime minister between
2001 to September 19, 2006, when he was ousted by a coup.

He has been sentenced to two years in jail on a corruption charge and now lives in self-exile, but remains a central player in Thailand's political drama.

The PAD, which has the tacit support of the military and other elements of Thailand's so-called "political elite," is dedicated to preventing Thaksin and his cronies from returning to politics.

"If Pracha is prime minister the PAD will be back on the streets and they might threaten to seize the airports again, but we have to show them they cannot dictate Thai politics" said Chaturon.

"Thailand's political problems will not be solved easily or quickly," he predicted. (dpa)