Workers load campaign billboards displayed on roadsides to promote candidates for a general election onto a truck in Bangkok, Thailand. The results of Sunday's general election will be formally announced on May 9. Picture: Gemunu Amarasinghe/AP

Bangkok - Thailand's pro-junta party won more votes than any other political party in last weekend's general election, the country's election commission announced Thursday.

Palang Pracharat, which is headed by junta leader Prayut Chan-o-cha, won 8.4 million votes, finishing ahead of anti-military party Pheu Thai, which received 7.9 million votes, according to Krit Eauwong, the deputy secretary-general of the election commission.

Progressive party Future Forward finished third with 6.2 million votes, while the Democrat party won 3.9 million votes.

But it was Pheu Thai party that won most constituency seats at 137, followed by Palang Pracharat at 97 seats, according to the commission. 

The vote tallies represent 100 per cent of the overall ballots cast, but the complete make-up of lawmakers remains unclear as the 150 party list candidates have yet to be calculated and included. 

The official results will not be announced until early May, pending investigations into reported irregularities which could lead to the disqualification of many candidates, the commission said. 

On Wednesday, Pheu Thai announced a coalition with six other parties in a bid to block the junta's continuation of power.

Together, anti-junta coalition could hold at least 255 seats, enough for a majority in the 500-member lower house but not enough for their candidate to be chosen as prime minister, which requires more than half of the votes in the 750-member parliament.

After five years of repressive military rule, Thais finally got to choose their own leadership on Sunday. 

But analysts say the election is neither fully free nor fair, as all of the 250 senators have been hand-picked by the military regime and will get to vote for the prime minister alongside the elected lower house in parliament, paving the way for junta leader Prayut Chan-o-cha to stay on as prime minister.

The commission has been subject to a lot of criticism since the Sunday election as many numbers reported were found to be miscalculated and election results have been repeatedly delayed, triggering the hashtag "Election Commission busted" on social media.

Some figures released on Wednesday did not seem to add up, while reported turnout was nearly 10 per cent higher than in a previous announcement, leading to concerns over the commission's accuracy and further fuelling suspicions of cheating.