BANGKOK (AFP) - Thailand's former ruling party on Sunday fought a bitter battle with the opposition to form a government, adding to the political uncertainty that has thrown the kingdom into crisis. The power struggle erupted a day after a surprise announcement by the main opposition group that it had won over allies of the People Power Party (PPP), which was dissolved by a court last week for vote fraud. The verdict followed months of protests against the PPP over its ties to ousted former premier Thaksin Shinawatra, culminating in a blockade of Bangkok's airports by royalist, anti-government protesters. With fears for the health of 81-year-old King Bhumibol Adulyadej, who was too sick to make a birthday-eve speech that many Thais hoped might offer a way out of the crisis, the choice of the next PM will be closely watched. "Our urgent mission is forming a government which came from elections," said Yongyuth Vichaidit, who was voted in as leader of Puea Thai (For Thais), a new banner under which the former ruling party has reformed. "Puea Thai is open for every coalition party to name a suitable candidate for prime minister," he added after the new party met to discuss how to keep its grip on power. Four small parties that had formed a coalition with Thaksin's allies after elections in December announced on Saturday that they had defected to the opposition Democrat Party to try and resolve the crisis. Puea Thai deputy leader Kanawat Wasinsangworn insisted that his party had enough seats to form a government, but their first task will be to lure back a faction that says it wants to join the Democrats. Former premier Somchai Wongsawat, who was stripped of his position by the same court ruling that barred the PPP, was quoted as saying that the fight was by no means over. "What happened is just the first round. Boxing has 12 rounds. There are many more rounds to go," the English-language Bangkok Post newspaper quoted him as saying. Somchai is Thaksin's brother-in-law. The anti-government People's Alliance for Democracy, which led the protests at Bangkok's airports, has threatened to hold further demonstrations if the new government is too close to Thaksin. Thaksin was ousted in a military coup in 2006 after similar demonstrations by the PAD, and the November 25 to December 3 shuttering of the main Suvarnabhumi international airport brought the country to a standstill. "There's been a political vacuum in Thailand since June or July," said David Streckfuss, a Thai historian with the University of Wisconsin. The protests stranded up to 350,000 travellers and battered the vital tourism industry. Tens of thousands of holiday-makers remain marooned as airlines clear the backlog. Thaksin was despised by PAD supporters in the old elite - which includes elements in the palace, military and bureaucracy - who felt that his popularity with poor, rural voters usurped some of their power. While living abroad after being sentenced in October to two years in jail for violating the kingdom's corruption laws, Thaksin has vowed to return to politics in his homeland. His powerful ex-wife Pojaman flew into Bangkok late on Friday, in a sign that Puea Thai's efforts to form a coalition were running into trouble. The former PPP has 212 seats from elections almost a year ago, although 37 of those are from a faction that could defect in part or whole, while the Democrat Party has 165 seats. The coalition parties have more than 60 seats in the 448-seat House of Representatives between them. If the Democrat Party manages to pull together a coalition, it could bring to power the party's leader, Oxford-educated Abhisit Vejjajiva, who is 44.