Thailand raised security on Saturday for its largest ever by elections, which will test support for the kingdom's new premier Abhisit Vejjajiva.
Authorities banned alcohol and deployed extra police in the 22 provinces voting on Sunday, when 29 lawmakers will be elected following a December court ruling that dissolved two political parties.
"Two police will guard each polling station and we have rapid movement units on standby to handle any unexpected situation," said General Wichian Potphosri, adding that he expected peaceful polls.
The by elections are the first electoral test for Abhisit, who took over following months of sometimes violent political protests culminating in a week long blockade of Bangkok's airports in November.
The 44 year old came to power after the parties' dissolution in early December, over voting fraud, which forced out the ruling coalition allied to former prime minister Thaksin Shinawatra.
Of the 29 seats vacated by the parties' dissolution, 13 belonged to the now defunct People Power Party, which led the previous coalition, and 16 seats were from their allies in the Chart Thai party.
Although the seats were previously held by followers of Thaksin, who was deposed in a 2006 coup, local media predicted a shoring up of support for the new government.
Those who defected to form the new coalition were expected to retain their supporters, leading media to predict the opposition Puea Thai party and its allies would pick up just eight of the 29 seats.
A total of 83 candidates from 13 political parties are on the ballots.