General elections were held in Thailand on 6 February, 2005. With a turnout of 60.7 percent, the Thai Rak Thai Party (Thais Love Thais Party) of Prime Minister Thaksin Shinawatra won a landslide victory. Out of 500 seats in the House of Representatives, Thaksin's party won 374 seats, with its former coalition partner, the Chart Thai Party (Thai Nation Party), taking 26 seats. The opposition Democrat Party of Thailand (Phak Prachatipat) won only 96 seats and the newly-formed Mahachon Party took three seats.
Thaksin said he would now form a one-party administration, ending his uneasy coalition with Chart Thai. The Bangkok newspaper The Nation said that Thaksin "has apparently won the strongest popular re-endorsement in Thai political history and is set to be the most powerful prime minister ever elected to lead the Kingdom." Thaksin is the first democratically elected Prime Minister of Thailand to complete a full four-year term in office and the first to win an absolute majority in the House in a relatively free election.
The day after the election, Thaksin said he would "work harder and faster to implement policies and resolve the country's problems." He said the government would "quickly boost Thailand's competitiveness in the international market, and would also look into improving religious affairs issues." This was taken as a reference to the situation in the south of the country, which has a large Muslim population, where there has been a history of unrest and disturbances, and where Thaksin's party won only one seat. The Nation newspaper reported: "Many voters [in the south] said they had lost faith in Thaksin, who has refused to apologise for incidents such as the deaths of 78 Muslims in October who were held in military custody after being arrested for protesting in the village of Tak Bai."
The national summary of seats by party follow:
| Party List|
| Thai Rak Thai|
|70 (+18)||126 (+42)||79 (+35)||1 (NC)||32 (+4)||67 (+19)||375 (+126)|
| Democrat Party|
|5 (-12)||2 (-3)||8 (-12)||52 (+4)||4 (-5)||25 (-6)||96 (-34)|
| Chart Thai Party|
(Thai Nation Party)
|0 (-3)||6 (-5)||11 (-8)||1 (+1)||1 (+1)||8 (+2)||26 (-13)|
| Mahachon Party|
(Great People's Party)
|1 (N/A)||2 (N/A)||0 (N/A)||0 (N/A)||0 (N/A)||0 (N/A)||3 (N/A)|
The House of Representatives (Sapha Poothaen Rassadorn) consists of 400 members elected from single-member constituencies and 100 members elected from national party lists on a proportional basis. At the January 2001 elections, Thai Rak Thai won 248 of the 500 seats, and gained a majority by forming an alliance with the Chart Thai Party (Thai Nation Party) of Banharn Silpa-Archa, which won 41 seats. Since then Thaksin's party has absorbed three minor parties, giving him about 300 seats in the legislature. The Democratic Party of Thailand won 128 seats in 2001.
Between the 2001 and 2005 elections the Thai party situation was simplified by the disappearance of minor parties. Nearly all seats were expected to go to Thai Rak Thai, Chart Thai and the Democratic Party. The only other significant party was the Mahachon Party (Phak Mahachon or "Great People's Party"), a breakaway group from the Democratic Party.
The Democrat Party, led by Banyat Bantadtan, did not seriously expect to defeat the coalition of the other two parties, but hoped to win 200 seats, which would have been a gain of 70 seats. However, intra-party conflicts between Banyat's southern faction and the Bangkok faction led by Abhisit Vejjajiva made this goal appear even less realistic. The Democrats also developed a populist agenda, promising more jobs, free education and health care, and combating crime and corruption. However, the party refused to give details of their policies.
The TRT's landslide victory cast doubt over the future of both party leaders, and Banyat resigned as Democrat Party leader immediately after the election. Abhisit Vejjajiva, Banyat's successor, said: "It will take a long time to revive the party because we need to look four years ahead and consider how to stay in the hearts of the people."
Thaksin's party replied that it had provided Thailand with a stable, competent and corruption-free government, although critics said that corruption has actually increased under Thaksin's watch. Party spokesperson Suranand Vejjajiva said that Thais Love Thais was "the first party which could translate its populist policies into action. Its achievements and Mr Thaksin's vision give the party a clear edge and it will win an absolute majority," he said.
Thai politics tend to be regionally based. Thai Rak Thai is strongest in the north-east region (Isan), the poorest and most populated part of the country, where Thaksin's populist policies are most popular. TRT is also dominant in the north, since Thaksin was born in Chiang Mai and has directed much government spending to his home region. Thai Rak Thai is strong in the Chao Phraya valley as well, although the region has historically been a stronghold of Chart Thai, which still dominates in some of the central provinces. Voters in Bangkok, the wealthiest part of the country, are less predictable, but steady economic growth, goal-oriented campaign agendas like “Healthy Bangkok” and “10 new MRT lines across the capital” , and the publicity Thaksin received after the Great Indian Ocean Tsunami was enough to swing the allegiance of the capital's middle-class to TRT. The Democrats are strongest in the south, but are popular among liberal-minded voters in Bangkok.
During 2004 most observers suggested that Thaksin's popularity had declined since its peak in 2003, and that he was unlikely to achieve an absolute majority for his own party. The deaths of Muslim protesters in southern Thailand and the bird flu outbreak were seen as issues which the Thaksin government had handled poorly.
Veera also pointed out that the provinces directly affected by the tsunami were part of the Democrat Party's southern stronghold, and that Thaksin's high profile, particularly on state television, in delivering aid to the area might improve his party's chances of winning more seats in the south. "The Democrats might cry foul that Mr Thaksin is using the state media for campaign purposes," Veera wrote, "but the people may think otherwise." Only a miracle, he wrote, could turn the "tsunami tide which is now clearly in favour of Mr Thaksin." In the event the Democrats retained their dominance in southern Thailand, winning 50 of the 52 southern seats for which figures are available.