In a brief press conference early on Monday afternoon, commission secretary-general Jarungwit Phumma attributed conflicting vote count figures released on Sunday night to “human error”, and pledged to investigate all irregularities if the evidence was strong enough.
The commission called off the release of results at the last minute on Sunday night.
On Monday, the Pheu Thai party – which is estimated to have bagged the most number of seats in the Lower House – issued a statement demanding a probe into some three million “ghost” ballots that appeared in 10 provinces.
In Chiang Rai and Chiang Mai provinces, it alleged, the number of ballots cast exceeded the number of eligible voters by over 400,000 in each province. This phenomenon was detected in Bangkok as well, it alleged.
On Twitter, “Election Fraud” in the Thai language was a top-trending hashtag.
Pheu Thai’s chief rival is the Palang Pracharath Party, which is aligned with the five-year-old military government and is trying to get prime minister and former coup leader Prayut Chan-o-cha returned as premier.
According to the Election Commission’s tally, with 94 per cent of the votes counted, Palang Pracharath had secured 7.7 million votes and Pheu Thai 7.2 million. In third place was the Future Forward Party, with 5.3 million votes.
But it is the number of constituency seats held by each party, not total votes secured, that will determine who will dominate the 500-seat House of Representatives.
According to unofficial tallies by local media agencies, Pheu Thai won the most seats in the Lower House, though not enough to overturn the in-built numerical advantage that a junta-aligned Senate gives to parties supporting Mr Prayut.
Under the Constitution introduced after the 2014 coup, 250 appointed senators, mostly handpicked by the junta will vote jointly with the elected 500 Lower House members on their choice of prime minister.
To wield power in Parliament, a party or coalition must secure at least 376 seats, representing more than half of the 750 combined Lower House and Senate seats.
With most of the 250 Senate seats already aligned with the junta, this means that pro-Prayut parties need only muster another 126 seats in the election in order get him chosen as premier.
Analysts warn, however, that this arrangement throws policymaking into uncertain territory, as a minority government may struggle to get future laws passed.
Pheu Thai belongs to a political faction linked to deposed and fugitive former prime minister Thaksin Shinawatra which has won every election since 2001. Royalist military factions, however, revile him for his populist policies mostly targeted at the populous upcountry regions.
This bitter divide had consumed the Kingdom until recently, with the entry of some seven million first-time voters with faint memory of the past turmoil.
On the eve of Thailand’s first election in eight years, the Royal Household Bureau issued a statement urging Thais to support “good people”.
There were some clear winners and losers.
The youthful Future Forward Party, a new party with a stridently anti-junta stance, bagged 86 seats, according to the 93 per cent vote tally by broadcaster Thai PBS, surpassing the 55 seats won by the Democrat Party, the traditional favourites of Bangkok voters.
The poor showing forced former prime minister Ahbisit Vejjajiva to step down from his position as Democrat leader on Sunday.