Thailand's deposed premier resigned from his once all-powerful party in a letter faxed from London on Tuesday, after more than 200 colleagues quit the organization in the wake of a military coup.

Ousted Prime Minister Thaksin Shinawatra insisted his Thai Rak Thai party would survive the fallout, but other key members and analysts pronounced the exodus and Thaksin's resignation as the death knell for the party that had dominated Thai politics since 2001.

"I have to resign because of the current atmosphere and to protect the future of the party," Thaksin said in a three-page handwritten letter, his first detailed statement since a military council ousted him from power on Sept. 19, accusing him of corruption.

In the letter, Thaksin defended himself against accusations of wrongdoing and described his departure as a sacrifice for the nation.

"I have ... decided to make a sacrifice by resigning from the leadership of the Thai Rak Thai party effective starting now," said Thaksin, who founded the party in 1998. "I have to apologize to party members and people who do not want me to resign. I want to stress that it is necessary."

Thaksin assigned deputy party leader Sudarat Keyuraphan to serve as the acting head of the party, but the move was largely seen as ceremonial since the coup leaders have banned all parties from engaging in politics.

CountryWatch: Thailand

One party leader pronounced the departures as the end of Thai Rak Thai, which means "Thais love Thais."

"The legacy of the Thai Rak Thai party is over," said Pongpol Adireksan, a deputy party leader.

He said that an executive order issued by the ruling military council Saturday "clearly showed that it aims to dissolve the Thai Rak Thai and shut the door for Thaksin to return to politics." He added that more than 200 party members had resigned since Saturday.

Democrat Party leader Abhisit Vejjajiva, whose party was in opposition during Thaksin's five years in power, said "there is nothing to stop Thaksin regrouping."

Others, however, said Thaksin now faces a major challenge should he want to return to politics.

"Thai Rak Thai built a huge brand-name in a short time," said Thitinan Pongsudhirak, a political science professor at Chulalongkorn University. "Even if he is allowed to come back, he'll have to build up a new brand."

Thaksin was overthrown in a bloodless coup while he was abroad on official business in New York. After the coup, he flew to London, where he has an apartment.

Thaksin was accused of widespread corruption and abuse of power that prompted mass anti-government protests earlier this year. Coup leaders said they intervened to avoid imminent, violent clashes between anti- and pro-Thaksin forces.

Thaksin defended himself against the accusations in his resignation letter.

"I worked all along in accordance with the rule of law and the constitution," he wrote.

Surayud Chulanont, a former army commander, on Sunday replaced him as interim prime minister.

Western nations and human rights groups have criticized the coup, and Surayud's appointment has done little to ease that disapproval.

The interim constitution empowers the coup leaders to remove the prime minister and Cabinet, and maintains restrictions imposed by the military, including curbs on press freedoms and limits on public gatherings.