By Martin Petty and Andrew R.C. Marshall
BANGKOK, Feb 2 (Reuters) - Thailand went to the polls under heavy security on Sunday in an election that could push the divided country deeper into political turmoil and leave the winner paralysed for months by street protests, legal challenges and legislative limbo.
The risk of bloodshed at the ballot remains high, a day after seven people were wounded by gunshots and explosions during a standoff between supporters and opponents of embattled Prime Minister Yingluck Shinawatra in a north Bangkok stronghold of her Puea Thai Party.
The usual campaign billboards, glossy posters and pre-election buzz have been notably absent this time, as will be millions of voters fearful of poll violence or bent on rejecting a ballot bound to re-elect the political juggernaut controlled by Yingluck's billionaire brother, Thaksin Shinawatra.
There were about a dozen people lined up on the pavement near the district office in Sathorn District in central Bangkok when the polls opened. Security was very low - each voting area was guarded by a single policeman with an antique pistol - and there were no protesters.
Thaksin, 64, is loved and loathed in Thailand, but his parties have won every poll since 2001. His opponents say he is a corrupt crony capitalist who rules by proxy from self-exile in Dubai.
Victory celebrations would be likely muted for Yingluck. With parliamentary seats unable to be filled and the prospect of violence disrupting voting, she could find herself on shaky ground, exposed to legal attacks and unable to pass bills and budgets crucial to reviving a stuttering economy.
Yingluck last week refused to postpone the election, even though a fifth of those registered for advanced voting were unable to cast ballots after protesters blocked polling stations in 49 of 50 Bangkok districts as part of a "shutdown" of key intersections in the city. In 28 southern constituencies, no votes will be cast because no candidates could sign up.
Some 130,000 security forces will be deployed across the country, 12,000 in Bangkok, National Security Council chief Paradorn Pattantabutr told Reuters.
"We're confident there won't be too much chaos," he said.
Polling stations opened at 8 a.m. (0100 GMT) and the Election Commission says results will not be available on the day. Its commissioners are worried about unrest and are braced for a deluge of complaints and challenges to the results.
"There's been a lot of obstruction, so much, every single step of the way," commission secretary-general Puchong Nutrawong told Reuters.
"We don't want this election to be a bloody election. We can get every single agency involved to make this election happen, but if there's bloodshed, what's the point?"
Anti-government demonstrators say Thaksin subverted Thailand's fragile democracy by entrenching money politics and using taxpayers' money for generous subsidies, cheap healthcare and easy loans that have bought him loyalty from millions of working-class Thai voters in the north and northeast.
With broad support from Bangkok's middle class and tacit backing of the royalist establishment, old-money elite and military, the protesters reject the election and want to suspend democracy, replacing it with an appointed "people's council" to reform politics and erode Thaksin's influence.
The latest round of tumult in the eight-year political conflict erupted in November and underscored Thaksin's central role in the intractable struggle, both as hero and villain.
Yingluck was largely tolerated by Thaksin's opponents but her party miscalculated when it tried to introduce a blanket amnesty that would have nullified a graft conviction against Thaksin and allowed him to return home.
Many Thais see history repeating after a cycle of elections, protests and military or judicial interventions that have polarised the country and angered Thaksin's "red shirt" supporters, who held crippling blockades in 2010 and have vowed to defend his sister from any overthrow attempt.
Thailand's military has remained neutral so far, but the judiciary has taken on an unusually large number of cases in the past two months in response to complaints against Yingluck and Puea Thai that could result in the party's dissolution and lengthy bans for its top politicians.
There is also a chance the election could be annulled, as it was in 2006, over a technicality. The Election Commission is expecting lawsuits to be filed demanding the election be voided.
The main opposition Democrat Party is boycotting the poll and the commission has already voiced concerns that it would result in too few legitimately elected MPs to form a parliamentary quorum.
With no quorum to re-elect a prime minister, it looks likely Yingluck could be a caretaker premier for months. Even with a fresh mandate, a stalemate is almost certain, giving her opponents more time to intensify their campaign against her and for legal challenges to be lodged.
"Yingluck will look weaker and weaker, heading a caretaker government with decreasing authority to govern, more vulnerable to the charges against her as the Bangkok blockades become unbearable," said Thitinan Pongsudhirak, an expert on Thai politics at Bangkok's Chulalongkorn University. (Additional reporting by Alisa Tang and Panarat Thepgumpanat; Editing by Mark Bendeich and Nick Macfie)