Tens of thousands of anti-government demonstrators massed peacefully across Thailand's capital yesterday in their latest bid to topple Prime Minister Yingluck Shinawatra before a February election that the main opposition party will boycott.

Ms Yingluck called a snap poll for February 2 to try to cool tensions but protesters want to scuttle the election to prevent her from renewing her mandate and perpetuating the influence of her self-exiled brother and former premier, Thaksin Shinawatra.

Thailand remains in an all-too-familiar deadlock after eight years of on-off conflict broadly between supporters and opponents of Mr Thaksin, whose populist political machine has won every election since 2001, with widespread support among the rural poor.

Chanting "Yingluck, get out", whistle-blowing protesters gathered at locations around Bangkok and set up stages in at least four places, bringing traffic to a halt at three main intersections and in two commercial districts.

"I hate Yingluck and I want to get rid of her because she does everything for her brother, not for Thai people," said Chaloey Thanapaisan, a 75-year-old protester.

Among the protagonists in Thailand's turmoil is an establishment elite with influence among judges and generals and which backs protests against governments controlled by Mr Thaksin, who they see as a tax-dodging crony capitalist who used his power to enrich his family and his clique of tycoons.

But to millions of rural working classes and farmers outside Bangkok, he is a benevolent billionaire who improved their living standards with cheap healthcare, easy credit and a raft of state subsidies.

Thailand's near-term future has become more uncertain following a decision on Saturday by the opposition Democrat Party to boycott the election, saying the democratic system had been distorted by Mr Thaksin and was failing Thais.

The boycott adds to concern Thailand could be left in political limbo if forces allied with the protesters block an election.