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By Nopporn Wong-Anan
BANGKOK, Dec 2 (Reuters) - Thai Prime Minister Somchai Wongsawat was banned from politics for five years and his party disbanded on Tuesday, spurring jubilant anti-government protesters to end their blockades of Bangkok's airports.
Government party members said they would switch to a new "shell" party, already set up, and vote for a new prime minister on Dec. 8, setting the stage for another flashpoint in Thailand's three-year political crisis.
Chavarat Charnvirakul, a construction mogul and first deputy prime minister, was named interim leader, an official said.
Anti-government protesters cheered Somchai's fall after only 2-½ months in power, brought down by a Constitutional Court ruling that disbanded the ruling party for vote fraud.
Protest leaders said they would halt all rallies, including crippling sieges of Bangkok's two airports which have stranded a quarter of a million foreign tourists.
"We've won!" shouted one of the protesters, Angkana Wongticha, as members of the People's Alliance for Democracy (PAD) went wild.
PAD leader Sondhi Limthongkul said they would pull out of Suvarnabhumi and Don Muang airports at 10 a.m. (0300 GMT) on Wednesday, but the protest halt was conditional.
"If a puppet government returns or a new government shows its insincerity in pushing for political reform, we will return," said Sondhi. He had accused Somchai of being a pawn of his brother-in-law, former prime minister Thaksin Shinawatra, who was ousted in a coup in 2006.
The airports operator said it would decide on Wednesday when passenger flights in and out of the capital could resume.
The chaos may soon be over for thousands of stranded travellers in Thailand, but the country's wider conflict between forces loyal to Thaksin and Bangkok's royalist elites looked set to drag on.
"The divisions are so deep, it's difficult to see how it could be over," said political analyst Giles Ungpakhorn of Bangkok's Chulalongkorn University.
The Constitutional Court also disbanded two other parties in Somchai's six-party coalition for vote fraud in the 2007 general election and barred their leaders from politics for five years.
Somchai's predecessor, Samak Sundaravej, was also removed by the courts for hosting a TV cooking show while in office.
Tuesday's rulings raised the risk of clashes between yellow-shirted PAD supporters and pro-government red-shirts, who surrounded the court and forced judges to find a new venue.
"The judgement was fixed," Rojarek Phalaburee, a government supporter from the northern province of Chiang Mai, said.
Hours before the court decisions, one person was killed and 22 wounded after a grenade was fired at protesters at Don Muang airport.
Thailand's revered King Bhumibol Adulyadej, who has intervened in previous political crises during his six decades on the throne, made no mention of the country's troubles during a short speech at a Trooping the Colour military parade in Bangkok.
STRANDED TOURISTS
Some 250,000 foreign tourists have been stranded by the sit-ins at Suvarnabhumi, a major Asian hub, and the domestic Don Muang terminal. It was not clear when flights would resume.
"We need time to check the safety and security systems," Serirat Prasutanond, acting head of Airports of Thailand, told Reuters. Before the PAD announced its withdrawal, he had said the airports would stay closed until Dec. 15.
The first cargo flight in a week left Suvarnabhumi on Tuesday, a welcome sight for a tourist- and export-dependent economy already suffering from the global financial crisis.
Finance Minister Suchart Thada-Thamrongvech told Reuters on Monday the economy might be flat next year, or grow by just 1-2 percent, after earlier growth forecasts of between 4-5 percent.
The travel chaos worried neighbours who were to attend a regional summit in Thailand in two weeks, prompting the government to postpone it until March 2009, a spokesman said.
The Thai baht edged up against the dollar and the stock market rose on optimism that political unrest might subside after the ruling, but shares soon fell back again.
Tom Byrne, sovereign regional credit officer for Asia and the Middle East at ratings agency Moody's, told Reuters it was "difficult to see an end to the destructive political polarisation in Thailand".
"We think the events of the past week will damage Thailand's near-term economic outlook and complicate policy making at a time when the government needs to respond coherently to the global recession," he said.
All six parties in the coalition government vowed to stick together and seek a parliamentary vote for a new prime minister on Dec. 8. Lawmakers who escaped the political ban would move to new "shell" parties to form another ruling coalition.
"The verdict comes as no surprise to all of us," said Jakrapob Penkair, a former minister and close ally of Thaksin.
"But our members are determined to move on and we will form a government again out of the majority that we believe we still have," he told Reuters. ($1=35.46 Baht) (Additional reporting by Bangkok bureau; Writing by Darren Schuettler; Editing by Mark Trevelyan)