UPDATE 2-Thai PM gets second parliament grilling

(Adds Samak's defence)

By Chalathip Thirasoonthrakul

BANGKOK, June 24 (Reuters) - Thailand's opposition leader launched a scathing but largely symbolic parliamentary attack on Tuesday against Prime Minister Samak Sundaravej, whose office remains under siege from hundreds of street protesters.

The two-day no-confidence debate is unlikely to create anything more than some bad headlines for Samak's five-month-old coalition, which can count on solid support from the overwhelming majority it secured in a December election.

In a 2-½ hour speech, Democrat party leader Abhisit Vejjajiva accused Samak of failing to tackle the impact of soaring fuel prices, stimulate a stuttering economy or quelling violence in the Muslim south.

"It has been four months of inefficiency and we can't allow this to drag on for a full four years," the Oxford-educated Abhisit said in the televised debate as his 73-year-old opponent sat quietly folding origami birds.

"Its efficiency in going after its rivals and protecting its cronies' interests is much greater than its efficiency in running the country," the 43-year-old Abhisit said.

In an hour-long reply, Samak said the accusations were based on jealousy, not facts.

"Today I have been groundlessly insulted by a man in his 40s who believes a 73-year-old like me doesn't know anything," Samak said.

The Democrats won 164 seats in December, the first poll since a 2006 coup against former Prime Minister Thaksin Shinawatra, compared to 316 for Samak's People Power Party (PPP) and its five coalition partners.

Samak appears to have agreed to undergo the censure motion to appease a street campaign by the People's Alliance for Democracy (PAD), the motley group of businessmen, academics and royalists whose campaign against Thaksin led ultimately to his removal in the 2006 coup.

Abhisit also attacked the government for its conduct in a spat over a disputed 900-year-old temple on the Cambodian border, in which the PAD accuses the government of ceding land near the temple to Cambodia, a charge the government denies.

No Thai government has ever lost a no-confidence motion, and the latest bid by the Democrats to topple Samak and seven PPP ministers does not look like it is going anywhere.

The PAD's month-long street campaign has upset investors, worried about anything from another military coup to policy paralysis at a precarious time for the economy.

The stock market has dropped more than 13 percent since the street rallies began, and Finance Minister Surapong Suebwonglee said on Monday the political tension might cause the economy to miss his target of 6 percent growth this year.

PAD leaders say they will only call off the protests after the resignation of the government, which they say is an illegitimate proxy for Thaksin.

"The longer it clings on to power, the more damage the country will get," said PAD co-leader Chamlong Srimuang, an ascetic Buddhist and former general who led thousands of people in an uprising against an army-led government in 1992. (Additional reporting and writing by Nopporn Wong-Anan; Editing by Ed Cropley and Jeremy Laurence)