Thailand's pro-military conservative force says it has agreed to join a coalition led by the Pheu Thai Party to form a new government, three months after the general election. The move could provoke public backlash, as Pheu Thai had pledged to eliminate military influence from politics.

The United Thai Nation Party made the announcement on Thursday. It campaigned in May's election, led by outgoing Prime Minister Prayut Chan-o-cha. The former military general spearheaded a coup in 2014.

Pheu Thai, which is affiliated with former Prime Minister Thaksin Shinawatra, won the second-most seats in the election. It trailed the Move Forward Party, whose pro-democracy agenda includes reforming the monarchy.

Pheu Thai took over efforts to launch a government after Move Forward failed in its eight-party coalition talks. Pheu Thai's envisioned coalition does not include Move Forward.

Pheu Thai is expected to nominate real estate tycoon Srettha Thavisin as its candidate for prime minister in a parliamentary vote set for Tuesday.