Embattled Prime Minister Thaksin Shinawatra abruptly announced Tuesday he will step down from office, bowing to a mounting opposition campaign seeking his ouster over allegations of corruption and abuse of power.

His announcement came after Thaksin met with Thailand's revered monarch, King Bhumibol Adulyadej, at his southern seaside palace.

"I am sorry that I will not accept the premier post," Thaksin said in a televised speech.

The 56-year-old leader said he would remain in a caretaker role until a successor is chosen, adding that his replacement would be elected once parliament resumes within the next 30 days.

"We have no time to quarrel," he said. "I want to see Thai people unite and forget what has happened."

Results from Sunday's election showed Thaksin's popularity had plummeted, and opposition forces had been gearing up to resume their anti-government protests.

It is unclear what role the king played in his decision, although Thaksin said in his speech that scores of world leaders would be arriving two months for the 60th anniversary of the monarch's accession to the throne.

Thaksin insisted he had helped the country since being first elected in a landslide in 2001. He was returned to office in 2005 and called Sunday's election to defuse the political crisis.

"As for many things that I have been accused of, this prime minister has never thought of doing anything wrong or evil to the country," he said. "I think I have done my best. If there is an opportunity in the future to explain my actions, people may have a clearer understanding."

The leadership change under popular pressure was the second in the past decade and a half, but this one came without bloodshed. In 1992, people protesting the rule of a military strongman were gunned down before Bhumibol stepped in to end the bloodshed, and usher in a period of stable democracy.

"I think it shows good intentions on the part of the prime minister to resolve the conflict right," said Sanan Kachornprasat, whose Mahachon party was one of the three that boycotted the election. "Apart from making his announcement, he has to show that he is willing to work with everyone right away."

Thaksin's party won 57 percent of Sunday's parliamentary election, but scores of voters abstained, according to preliminary results. There was a record high number of abstention ballots in Bangkok, where the anti-Thaksin movement is strongest, and in southern Thailand, a traditional stronghold of the opposition Democrat Party.

Thaksin's announcement late Tuesday was particularly surprising, given that he said on national television a day earlier that his party had won 16 million votes — meeting his threshold of staying in office if he won more than half of the vote.

In his remarks Monday, he acknowledged a strong protest vote against him and said he would set up a neutral committee to decide his political future. He said the committee would comprise three former prime ministers, three former Supreme Court chiefs and three former heads of Parliament to judge whether he should resign.

"If that committee tells me to quit, then I will quit," Thaksin said.

But Thaksin's critics, who for two months have been staging rallies drawing as many as 100,000 people, rejected the idea of a reconciliation committee as insincere and called for new protests this week.

The rallies grew in size after Thaksin's family in January said it had sold its controlling stake in telecommunications company Shin Corp. to Singapore's state-owned Temasek Holdings for a tax-free $1.9 billion. Critics alleged the sale involved insider trading and complained that a key national asset was now in a foreign government's hands.