Thailand will deploy 10,000 police in the capital Bangkok for Sunday's election.
Riot police on guard in Bangkok. Photo: AFP
Protestors are promising to disrupt the polls as part of a drawn-out attempt to topple Prime Minister Yingluck Shinawatra.
On Tuesday the government decided to press ahead with the election on 2 February, despite warnings that it could lead to more trouble without resolving an increasingly bitter political dispute.
Opposition protesters intend to disrupt the polls to stop the ruling party returning to power.
Ms Yingluck's ruling party is certain to win the election. However, the new parliament is unlikely to provide a working majority after the election.
"Even though protests are going on, I believe you can go out and vote. I ask everyone involved in the election, particularly security forces, to ensure that people can out and vote," she said on Wednesday.
Labour Minister Chalerm Yoobamrung, who is in charge of a state of emergency imposed last week, said 10,000 police would be mobilised in the capital on polling day.
"Those who are thinking of going and shutting polling stations in the morning should think twice because the police will not allow them to," he said.
Protesters prevented early voting at many polling stations in Bangkok last Sunday andhave vowed to do so again.
Eight years of conflict
The conflict is the latest round of a political struggle that has gripped Thailand for eight years.
Bangkok's middle class and royalist establishment is pitted rural supporters of Ms Yingluck and her brother, former premier Thaksin Shinawatra, who is in exile. He was deposed by the army in 2006.
The Election Commission, which is widely seen as favouring the opposition, had been arguing for a delay in the vote of up to four months, saying the country was too unstable to hold an election.
So far, the military has stayed firmly on the sidelines, in contrast to the past: it has staged or attempted 18 coups in 80 years of on-off democracy.
Ms Yingluck is Thailand's fifth prime minister since her brothers removal from power.
