Thailand's two main opposition parties are set to begin negotiations to form a ruling coalition after emerging victorious in the general election.

Preliminary results released on Monday by electoral authorities showed the Move Forward Party and the Pheu Thai Party came first and second, respectively, at the polls on Sunday.

The Move Forward Party, which calls for the elimination of military influence, has captured 152 seats in the lower house. Pheu Thai, a party affiliated with former prime minister Thaksin Shinawatra, got 141 seats.

Prime Minister Prayut Chan-o-cha's United Thai Nation Party won 36 seats. Prayut led a military coup nine years ago.

Move Forward Party leader Pita Limjaroenrat declared victory and showed a willingness to become prime minister. He said his party seeks a completely democratic parliament and that it would start coalition negotiations with Pheu Thai and other parties.

Paetongtarn Shinawatra, who is a daughter of the former prime minister and a Pheu Thai candidate for prime minister, acknowledged that she agreed in a call with Pita that their parties would enter coalition negotiations.

The two opposition parties have a combined majority in the lower house. But they are at odds over some issues, including the lese majeste laws that forbid insulting the royal family, which the Move Forward Party seeks to amend.

It remains to be seen whether the two parties will be able to form a coalition government and replace the military-led government. Observers say Pheu Thai may lean toward forming a coalition with other parties.