Voters in Thailand will elect a new government Sunday. Opinion polls are predicting that Prime Minister Thaksin Shinawatra will win a historic second term.

At his final rally in Bangkok on Friday night, Mr. Thaksin urged the crowd to give him a strong mandate so that his Thai Rak Thai party could govern without coalition partners. He said a single-party government during his second term would allow him to complete his program of eliminating poverty in Thailand.

Mr. Thaksin is well ahead in the polls and opposition parties, led by the Democrat Party, have appealed to voters to give them more than 200 of the 500 seats in the House of Representatives. This would allow them to keep the government in check and prevent what they call a single-party dictatorship.

The Thai Rak Thai party, which came to power in 2001, is the first civilian government in Thailand to complete a full term. Previous civilian governments collapsed because of party defections or military coups.

Forty-four million voters are eligible to cast their ballots Sunday at 83,000 polling stations across the country. They are choosing from more than 2,300 candidates for the lower house.

The campaign has been marred by a dozen election-related killings. Mohamad Herizal of the Amfrel election-monitoring group says his organization has received complaints of patronage politics.

"We have received complaints by various people saying that the incumbent party are using national resources for their political dynasty and we do look into cases like this," said Mohamad Herizal.

Mr. Herizal says his group has not found proof so far of the charges.

Mr. Thaksin says the political stability of the past four years has allowed him to restore prosperity after the economic downturn caused by the Asia financial crisis of 1997.

However, his critics say the prime minister's autocratic style has rolled back democratic advances made since the end of the military era more than a decade ago. And human rights groups accuse his government of heavy-handed tactics in campaigns to suppress illegal drug trafficking and a separatist insurgency in the Muslim-dominated south.

Election security is particularly tight in southern Thailand, where more than 500 people have been killed in the past year in a wave of violence.