BANGKOK, Thailand -- Former Thai Prime Minister Thaksin Shinawatra, deposed by a military coup 17 months ago, will return from exile Thursday to fight corruption charges, the foreign minister said.

Critics warned the billionaire-politician's homecoming could plunge the country back into the kind of crisis that precipitated his fall. A leading anti-Thaksin group has already announced plans to mobilize protesters.

The prospect of Thaksin's imminent return sent shock waves through the country's political circles, prompting the new prime minister, Samak Sundaravej, to call for calm.

"I want to urge the Thai people not to be concerned," Samak told reporters Tuesday. "I do not anticipate any unwanted incidents. There will be no chaos." Samak heads the People's Power Party, widely regarded as a proxy for Thaksin, who is barred from political office.

Foreign Minister Noppadon Pattama, a close ally of Thaksin and his former lawyer, met with Thaksin in China over the weekend.

"As far as I know from my meeting with him, he will return Thursday," Noppadon told The Associated Press.

Thaksin himself has not yet publicly announced his plans, though he said earlier he expected to return by March or April.

Thailand became deeply polarized two years ago, when large protests were held demanding that Thaksin step down after five years as premier because of his alleged corruption and abuse of power.

A deadlock between Thaksin and his foes was broken by the Sept. 19, 2006 coup that ousted him while he was abroad, and he has since stayed in exile. But after interim rule by a military appointed government, the People's Power Party won the most seats in a general election last December and formed a six-party coalition government earlier this month.

Thaksin will be provided police security upon his return, said army commander General Anupong Paochinda, who was one of the coup leaders. He called for caution, saying that "a third hand might take the opportunity to cause trouble," but did not elaborate.

On Tuesday, Thaksin's official website posted a picture of the deposed prime minister with his right hand raised giving the victory sign, superimposed over an image of Bangkok's international airport as fireworks exploded overhead. It urged supporters to greet Thaksin at the airport at 9 a.m. Thursday.

"Welcome home Prime Minister Thaksin Shinawatra, whom we love, miss and have been waiting to return for over a year," the website said in Thai.

The chief of Thaksin's legal defense team, Pichit Chuenban, said Thaksin will surrender to police when he arrives and will seek his release on bail.

Thaksin and his wife Pojaman face corruption and conflict of interest charges in connection with her purchase of prime Bangkok real estate from a state agency in 2003, while he was prime minister. Pojaman returned to Thailand in January and was released on bail pending trial.

Thaksin also faces separate charges of concealing assets. Rakkiat Wattapong, the Supreme Court secretary general, said Monday that Thaksin would be detained when he arrives in Thailand.