Bangkok  - Thais went to the polls Sunday to vote for 29 new legislators in a by-election and for a new governor in Bangkok, with the outcome of both polls likely to test the strength of the current coalition government.

The by-election was called in 22 provinces after the Constitution Court last month dissolved the People Power Party and Chart Thai parties for committing fraud in the December 2007 polls. The decision barred their top executives from political office and left 29 seats vacant in the lower house.

The court decision led to the establishment of a new coalition government under the lead of the Democrat Party, the former opposition, with Abhisit Vejjajiva as prime minister.

Of the 29 contested seats, 13 earlier belonged to the PPP and the remaining 16 seats were held by its allies in the Chart Thai Party.

The PPP has since transformed into the Peau Thai Party, the opposition, whereas the Chart Thai remnants have joined the Democrat- led coalition.

Having been voted in to office with a 235-198 victory, Abhisit holds a slim majority in Parliament, making the outcome of the by- election important to the government's future stability.

In Bangkok, one of the chief contenders in the gubernatorial race is Democrat candidate Sukhumbhand Paribatra, who is of royal decent. His victory in Bangkok would strengthen the Democrats' hold on the politically pivotal metropolis, whose denizens have toppled more than one elected government in the past.

Sukhambhand's main rival is Yuranan Pamornmontri, the candidate of the Peau Thai opposition party. Results of the gubernatorial polls are expected to be known by midnight Sunday. (dpa)