Thailand's main opposition Democrat Party on Saturday announced it would boycott snap elections in the crisis-gripped kingdom, piling further pressure on the government as protesters prepared to ramp up rallies aimed at suspending democracy.
Members of the kingdom's oldest political party -- who resigned as MPs en masse to join the demonstrations that have rocked Bangkok for weeks -- voted against participating in the poll, according to Democrat leader Abhisit Vejjajiva.
"The Democrats think the elections will not solve the country's problems, lead to reform, or regain people's faith in political parties," he said in a press conference following the meeting, adding that the political system was a "failure".
Embattled premier Yingluck Shinawatra, who called the February 2 elections in an effort to cool tensions, has insisted the polls will go ahead regardless of the Democrat decision.
But the move throws Democrat backing firmly behind protesters who are calling for democracy to be paused for an unelected "people's council" to be installed to enact reforms before a future vote.
Demonstrators want to rid the country of Yingluck and the influence of her Dubai-based brother Thaksin -- an ousted billionaire ex-premier who is despised by a coalition of southerners, the Bangkok middle classes and elite.
The Democrats previously boycotted elections in 2006, helping to create the political uncertainty which heralded a military coup that ousted Thaksin.
The latest boycott could lead to a similar situation, with polls "nullified" on technical grounds, said Pavin Chachavalpongpun, a former Thai diplomat and associate professor at the Centre for Southeast Asian Studies at Japan's Kyoto University.
"Walking away from it, it's just bad on the part of the Democrat Party. Especially if (the) international community is now watching the Thai situation so closely," he said in comments ahead of the meeting.
Thailand has seen several bouts of political turmoil since Thaksin was deposed, with rival protests sometimes resulting in bloody unrest.
"I think if the Democrats ran in the election, we might get the most votes and be able to form a government -- but then again people will be mobilised to rally against our party," former premier Abhisit said.
He added that the decision would not affect the "legitimacy" of the vote and the party would not "obstruct" polling.
The boycott announcement comes a day ahead of a planned major rally by the protesters, who are led by firebrand former Democrat MP Suthep Thaugsuban.
Demonstrators want Sunday's gathering to be bigger than earlier protests, which have drawn at least 150,000 supporters at their peak in some of the largest protests for years in the politically-divided kingdom.
Suthep, who has vowed to rid Thailand of the "Thaksin regime", has dismissed the election, saying it will install another government allied to the divisive former premier.
He has appealed for army support, in a country which has seen 18 successful or attempted coups since 1932.
But the military has indicated it is unlikely to intervene directly this time.
"The Democrats want to create the same situation that we had in 2006 and pave the way for coup," said Thida Thavornseth, leader of the pro-Thaksin "Red Shirts", adding that they "no longer exist as political party".
On Friday the Democrats sent a letter to other parties requesting a postponement of the polls because of the ongoing protests.
But the suggestion was rejected by Yingluck's Puea Thai party, which is widely expected to win the election.
"There is no problem with the election," Puea Thai spokesman Prompong Nopparit told AFP, adding that more than 60 parties would take part.
Yingluck on Saturday offered to set up a body to implement reforms, but insisted it could operate alongside an elected government.
The Democrats have not won an elected majority in some two decades.
The party last took power in 2008 by parliamentary vote after a court stripped Thaksin's allies of power, angering the Red Shirts who launched mass street protests three years ago that ended in a military crackdown that left dozens dead.
Thaksin is adored among rural communities and the working class, particularly in the north and northeast, but the billionaire tycoon-turned-politician is reviled by the elite, who see him as corrupt and a threat to the monarchy.
Pro-Thaksin parties have won every election since 2001, most recently with a landslide victory under Yingluck two years ago.