Almost one-fifth of the seats contested in Thailand's general election are being investigated over alleged voting irregularities, officials say.
The election was the first since a bloodless coup in 2006
Provisional results had given victory to the People Power Party (PPP), with 233 of the 480 available seats.
But 65 of those seats are among the 83 being investigated, mostly amid accusations of vote-buying.
The PPP did not gain an overall majority, but claims to have struck a deal to form a coalition government.
The party, which supports ousted former Prime Minister Thaksin Shinawatra, announced on Monday that three smaller parties would join its administration.
But the Electoral Commission's investigation has cast doubt over the PPP's coalition plans.
Three PPP politicians were disqualified last week on charges of vote-buying, and the party could yet have more seats taken from it.
Six of the 165 seats won by the second-place Democrat Party are also under investigation.
The official results of the poll were expected on Thursday but were delayed by the investigation into irregularities.
At a news conference, the commission's chairman Apichart Sukhakkanon said 397 seats had been confirmed and the MPs endorsed without protest.
Kudeb Saikrajang, a spokesman for the PPP, said the party was confident that the commission was investigating fairly.
"We are waiting for its results. We believe we can go ahead with launching our coalition government," he said.
The apparent PPP victory was a major blow for the generals who ousted Mr Thaksin in a coup in September 2006.
The PPP has openly said it will seek to be advised by Mr Thaksin and will let him return from self-imposed exile in the UK.