BANGKOK, THAILAND - Thailand's opposition Democrat Party launched a largely-symbolic no-confidence motion on Tuesday against Prime Minister Samak Sundaravej, whose office remains under siege from hundreds of street protesters.

The two-day parliamentary debate is unlikely to create anything more than some bad headlines for the five-month-old coalition, which can count on solid support from the overwhelming majority it secured in a December election.

'There has been no single time in the history of Thai democracy that a coalition government with a majority has lost in a censure debate,' said political scientist Boonyakiet Karavekpan of Bangkok's Ramkhamhaeng University.

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

Instead, Mr Samak appears to be using the no-confidence motion to counter the street campaign by the People's Alliance for Democracy (PAD), the motley group of businessmen, academics and royalists whose campaign against Mr Thaksin led ultimately to his removal in the 2006 coup.

But chief opposition whip Mr Satit Wongnongtaey said the motion, which also targets seven PPP cabinet ministers, could trigger a snap election.

'We believe our evidence and information will convince the other five coalition partners to abandon their trust in the prime minister,' Mr Satit said.

He said the Democrats would focus on the government's handling of the economy at a time of soaring inflation and stuttering growth, as well as its conduct in a spat over a disputed 900-year-old temple on the Cambodian border.

The PAD accuses the government of ceding land near the temple to Cambodia, a charge the government denies.

The 73-year-old Samak faced a similar attack in the Senate on Monday.

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 per cent 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 per cent 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. -- REUTERS