The election pitted those advocating far-reaching change, the People's Party, against conservatives led by incumbent PM Anutin Charnavirakul, with most polls predicting a close race between the two.

When the young reformers won last time, the military-appointed senate barred them from forming a government and the constitutional court dissolved the party. Powerful, unelected forces have repeatedly intervened to block parties challenging Thailand's status quo. Results will become clear around 22:00 local time (15:00 GMT).

The People's Party is facing a strong challenge from Anutin, who has built his once small, provincial Bhumjaithai - "Thai Pride" party - into the standard-bearer for Thai conservatives. The latest opinion polls and early vote counts suggest no party will win a majority in parliament, with Anutin expected to remain prime minister. He has played on patriotic sentiment after the two short border wars with Cambodia last year, and promising to defend the status of traditional Thai institutions like the monarchy and military.

The third main contender is the Shinawatra family and its Pheu Thai – "For Thais" – party. In the past it dominated elections, with well-marketed populist policies. It has promised to create nine new millionaires – in Thai baht – every day through a national prize draw. Both Bhumjaithai and Pheu Thai have offered subsidies and cash handouts to voters. Pheu Thai, however, is expected to lose significant support in this election after its last coalition administration was accused of mishandling the conflict with Cambodia, and its patriarch, former PM Thaksin Shinawatra, was sent to jail. (BBC)