(Adds protest leader saying won't block people from voting)
* Army to increase troops in capital ahead of election
* Minister fears violence if protesters block vote
* About 10,000 police responsible for security in Bangkok on election day (Adds comment from protest leader)
By Amy Sawitta Lefevre and Khettiya Jittapong
BANGKOK, Jan 30 (Reuters) - Thailand's army will increase the number of troops in the capital ahead of Sunday's election, it said on Thursday, as the government warned it might not be able to contain violence if anti-government protesters try to stop people voting.
The protesters, members of the People's Democratic Reform Committee (PDRC), had said they would disrupt the ballot as part of their campaign to overthrow Prime Minister Yingluck Shinawatra, but their leader appeared to backtrack.
The government's decision to press ahead with the election has inflamed tension in the capital, Bangkok, where the protesters have blockaded main intersections and forced many ministries to close their doors this month.
"In addition to the 5,000 soldiers we have already deployed in and around Bangkok to help monitor security, we will be increasing troops around protest sites as there are people trying to instigate violence," army spokesman Winthai Suvaree told Reuters.
About 10,000 police would be responsible for Bangkok security on Sunday and the troops would be on standby.
Labour Minister Chalerm Yoombamrung, in charge of a state of emergency imposed last week, urged the protesters not to disrupt the vote.
"If the PDRC do that, people will beat each other to a pulp and nobody can control a situation like that," he told reporters. "The police and soldiers don't have enough manpower to take care of (security) at every polling station."
Protest leader Suthep Thaugsuban said people should not waste time voting but appeared to drop earlier plans to try to obstruct polling.
"Those who want to vote should go and vote," he told supporters as the sun set. "We won't block you from voting otherwise you'll turn around and say we violated your rights."
Demonstrators took to the streets in November in the latest round of an eight-year conflict that pits Bangkok's middle class, southern Thais and the royalist establishment against the mostly poor, rural supporters of Yingluck and her brother, former premier Thaksin Shinawatra, who was ousted in a 2006 coup.
The protesters accuse Yingluck of being a puppet of former telecoms tycoon Thaksin, a man they say is a corrupt crony capitalist who disrespected the monarchy and bought elections over the past decade with costly populist giveaways.
Thaksin, who denies that, went into self-exile in 2008, shortly before he was sentenced to jail on graft charges he says were politically motivated.
Ten people have died and at least 577 have been wounded in politically related violence since Nov. 30 according to the Erawan Medical Center, which monitors Bangkok hospitals.
A protest leader was killed and about a dozen people were injured in a clash near a polling station during advance voting on Sunday. The protesters prevented early voting in many parts of the capital and the south.
The violence is the worst since 2010 when Suthep, at the time a deputy prime minister, sent in troops to end demonstrations by pro-Thaksin activists.
Suthep faces murder charges related to his role in that crackdown, when more than 90 people were killed, and for insurrection in leading the latest protests which are also taking their toll on Southeast Asia's second-largest economy.
Consumer confidence fell for the ninth month in December, hitting a two-year low and the central bank said last week the economy may grow only 3 percent this year rather than the 4 percent it had forecast.
Tourist arrivals have been hit in the peak season and huge infrastructure projects have been put on hold.
Toyota Motor Corp, one of Thailand's biggest foreign investors, said it hoped for a quick solution to the political crisis.
"The region is like the Detroit of Asia and many makers are exporting from there too," Toyota President Akio Toyoda told reporters. "We hope that the situation will be resolved as soon as possible so that the global impact will be limited."
Thailand is the region's biggest car-making hub.
Suthep led a march in the capital under a blazing tropical sun on Thursday, the start of a three-day push to demonstrate opposition to the vote and rustle up support for its cause.
He wants political reforms before an election is held, with the aim of eradicating the influence of Thaksin and his family. They have not said how they would do this.
Shop and office workers cheered on the marchers, numbering between 2,000 and 3,000 according to a Reuters estimate, offering food, drinks and money.
Yingluck's Puea Thai Party is expected to win the election comfortably with the main opposition Democrat Party boycotting the vote.
However, not enough candidates have been able to register to provide a quorum for parliament to elect a new government after the election. By-elections will have to be held to fill the vacant seats, which could leave the country without a properly functioning government for months. (Additional reporting by Yoko Kubota in TOKYO; Editing by Alan Raybould, Nick Macfie and Robert Birsel)