Data from the election commission showed a high voter turnout of 91.83 per cent in the advance voting on Sunday.
Their ballots, which are contained in sealed envelopes, will be sorted and dispatched to their respective constituency by May 12.
“When the envelopes reach the constituencies, they will be kept in a secure place and at 5pm on the election day – May 14 – the officials at the polling station will retrieve and count them alongside the ballots cast on that day,” Mr Sawaeng explained.
About 52 million people are eligible to cast their votes on Sunday to elect 500 members of the House of Representatives.
Four hundred of them will be chosen in constituency elections. The other 100 will be elected from the national party lists – a type of proportional representation where multiple candidates are elected from a list prepared by their respective parties, based on the total votes the party receives.
Later in parliament, a prospective prime minister will be chosen – a decision that must be approved by more than half of the combined 750-member assembly, which also includes 250 members of the Senate.
Voting on Sunday will take place from 8am to 5pm. After the ballot boxes are closed, vote counting will begin. The public can observe the process.
“I believe this process will ensure every single vote cast by eligible voters truly reflects their choices,” Mr Sawaeng said.