Voters in Thailand have cast their ballot to elect the upper house of parliament, in a poll that could hold the key to the fate of the prime minister, who faces possible impeachment for negligence after months of street protests.
Thais voted on Sunday for half of the 150-seat Senate in a key test for Yingluck Shinawatra's troubled government, a day before she is due to defend herself against negligence charges over a disastrous rice subsidy scheme.
Thailand's 150-seat Senate is made up of 77 elected senators. The other 73 seats are appointed and are seen as opponents to the government.
The government's opponents want to ensure a conservative, pro-establishment, majority to influence any decision to remove Yingluck which would require the votes of three-fifths of the senators.
While the Senate is officially non-partisan, in reality the two main political camps are vying for control of the chamber, in the absence of a functioning lower house following incomplete February polls.
Yingluck has resisted massive pressure to step down despite months of street protests and a slew of legal moves against her - including over her alleged role in a rice subsidy scheme that could lead to an impeachment vote in the Senate.
Polls closed on Sunday afternoon, according to an election official, who said there was no repeat of the widespread disruption caused by anti-government protesters to a February 2 general election, which was also boycotted by the main opposition party.
That vote was voided by the Constitutional Court earlier this month.
"Today's election went smoothly... if the parties concerned create a stable political situation then an election can be successful," Election Commissioner Somchai Srisutthiyakorn told reporters.
Six-month political standoff
With Thailand's political crisis lurching towards its sixth month, the Senate polls have taken on fresh importance.
Preliminary results are due late Sunday but the official list of newly elected senators could take days to approve.
At a central Bangkok polling station a steady streams of voters cast their vote, according to AFP reporters.
"Elections are best for democracy. Whatever we do, we must have elections," said 65-year-old voter Amnuay Aransri.
Thailand has seen years of political conflict and rival street protests by opponents and supporters of Yingluck's brother, fugitive former premier Thaksin Shinawatra who was ousted in a coup in 2006.
The billionaire tycoon-turned-politician, who clashed with the royalist establishment, fled overseas in 2008 to avoid jail for a corruption conviction, but he is seen as the de facto leader of his sister's Puea Thai party.
Yingluck has faced months of mass rallies demanding she step down to make way for an unelected interim government to oversee reforms.
Political violence, often targeting protesters, has left 23 people dead and hundreds wounded in grenade attacks and shootings in recent months, although the bloodshed has abated since the demonstrations were scaled back at the start of March.