Pheu Thai and 10 other parties, two linked to the military, on Monday afternoon announced a coalition with 314 votes in the House and Pheu Thai's Srettha Thavisin as their candidate for prime minister.
Pheu Thai, which came second in the May 14 general election with 141 elected MPs, is the biggest component of the 11-party alliance.
Three other allies are Bhumjaithai with 71 seats, Palang Pracharath (PPRP) with 40 seats and United Thai Nation (UTN) with 36 seats. They came third, fourth and fifth in the election.
The seven other partners are Chartthaipattana (10 MPs), Prachachat (9), Pue Thai Rumphlang (2) Chartpattanakla (2), Seri Ruam Thai (1), Plung Sungkom Mai (1) and Thai Counties (1).
Pheu Thai leader Cholnan Srikaew told a press conference at the parliament about 1.30pm that Pheu Thai would have eight ministers and nine deputy ministers, including the PM's Office ministry.
Bhumjaithai will have four ministers and four deputy ministers; PPRP two ministers and two deputies; UTN two ministers and two deputies; Chartthaipattana one minister and Prachachat one minister.
PPRP has caretaker Deputy Prime Minister Prawit Wongsuwon as its leader, while UTN earlier had caretaker Prime Minister Prayut Chan-o-cha as its prime ministerial candidate.
The coalition parties agreed to treat Pheu Thai's policies as important polices for the new government. They include the digital wallet policy, 600-baht minimum daily wage and higher farm prices, the Pheu Thai leader said.
They would have a constitution-drafting assembly set up to amend the constitution to make it "more democratic", he said.
Section 112 of the Criminal Code (the lese majeste law) and other chapters concerning the royal institution would remain intact, Dr Cholnan said.
The Pheu Thai leader said he acknowledged the heavy criticism of Pheu Thai for teaming up with parties in the caretaker government. "But we will join forces to work efficiently", he said, in apparent reference to PPRP and UTN.
At the beginning of the press conference, Dr Cholnan stated clearly that the coalition would not include the Move Forward Party.
MFP won the general election with 151 House seats. Pheu Thai withdrew from the MFP-led coalition alliance early this month.