Bangkok, Thailand (CNN) -- Thai anti-government demonstrators say they will keep up protests in Bangkok ahead of a controversial national election in a nation gripped by a bitter, protracted political crisis.
The protesters have been campaigning for months against Prime Minister Yingluck Shinawatra, fueling unrest that has left 10 people dead and hundreds more wounded.
The instability has created fears of political chaos in Thailand, which was shaken by severe bout of violence four years ago. The concerns have already hurt the country's lucrative tourist industry and undermined investment in one of Southeast Asia's main economies.
Yingluck called the elections in December in a bid to ease mounting tensions on the streets of Bangkok. But the demonstrators and the main opposition party with which they're affiliated have already rejected the vote, which Yingluck's party is expected to win comfortably.
State of emergency
Authorities have tightened security ahead of the vote Sunday, with 10,000 security personnel on standby.
Protest leaders want to replace Yingluck's administration with an unelected "people's council," which would push through electoral and political changes. They say they want to rid Thailand of the influence of her older brother, the divisive former Prime Minister Thaksin Shinawatra, who is living in self-imposed exile.
In recent weeks, the anti-government demonstrators have blocked candidate registrations and early voting in parts of Bangkok and southern Thailand, the regions from which they draw their support. Those efforts to undermine the election have resulted in clashes with pro-government groups, whose power base is in the north and northeast of the country.
Amid the bursts of violence, Thai authorities declared a state of emergency last week, giving extra powers to security forces and drawing criticism from human rights advocates.
But the government says it has no plans to use force against protesters, who plan to hold marches in central Bangkok on Friday and Saturday.
The protest leaders say they want as many of their supporters as possible to join them Sunday in the streets of Bangkok for what they describe as a "picnic" that they hope will shut down the city on the day of the election.
But the numbers of demonstrators involved in a previous attempt to bring Bangkok to a standstill in early January quickly ebbed. Groups of them continue to gather at major intersections in the center of the city where they try to block traffic.
Their mood remains spirited. But on Thursday evening, they numbered around 7,000, police said, far fewer than the more than 150,000 who assembled in early January.
The main protest leader, Suthep Thaugsuban, a former deputy prime minister for the opposition Democrat Party, says he is encouraging Thai people not to vote in the election.
In some areas of southern Thailand, anti-government demonstrators continued to block post offices Thursday, preventing election officials from collecting ballot papers.
'A guiding light'
Yingluck has been under pressure since November after a botched attempt to pass an amnesty bill that would have opened the door for Thaksin's return stirred anger around the country.
Yingluck said Thursday that the election would be "a meaningful one" and "a guiding light" for the future of democracy in Thailand.
She has rejected calls to postpone the election despite concerns it could prompt an intensification of civil unrest without resolving the country's extended political crisis.
"The election is one of the best and peaceful mechanisms to end conflict between people of different political views, and a way to reflect majority's needs and minority's voices," Yingluck said in a statement Thursday.
But her party's probable success in the vote appears unlikely to deter protesters. The demonstrators' efforts to disrupt registration for the election could mean there aren't enough candidates for a new parliament to open.
Pro-government groups, known as the red shirts, say they will hold rallies in several provinces Friday in support of the election. But they didn't announce any plans for demonstrations in Bangkok, where the anti-government protesters are holding marches.
Suthep's anti-government protesters say Yingluck is merely a puppet of Thaksin, a polarizing figure who built his support on populist policies that pleased residents of the north and northeast. Yingluck has repeatedly denied her brother calls the shots in her government.
Thaksin, a business tycoon whose electoral success unsettled Thailand's establish elite, was ousted in a military coup in 2006 and has spent most of the time since then in exile overseas. If he returns, he risks a two-year prison sentence on a corruption conviction, which he says was politically motivated.
The anti-government demonstrators stated goal of ridding Thailand of Thaksin's influence appears ambitious in a country where parties affiliated with him have won every election since 2001.
Thailand's worst bout of civil unrest took place in 2010, when the government -- run at the time by the Democrat Party -- ordered a crackdown on red shirt protesters, leaving about 90 people dead.
CNN's Kocha Olarn and Saima Mohsin reported from Bangkok, and Jethro Mullen reported and wrote from Hong Kong. CNN's Pamela Boykoff and journalist Pichit Phromkade contributed to this report.