Thailand's progressive voters celebrated victory in May's general election. But they've since seen their party forced out of plans to build a new government. And now, the second-largest Pheu Thai party is forming a coalition with the country's hardliners.

The new alliance includes the pro-military United Thai Nation Party, which campaigned in May under outgoing Prime Minister Prayut Chan-o-cha, and the Palang Pracharath Party, which played a key role in his administration.

Pheu Thai leader Cholnan Srikaew insisted they will all be working together.

Pheu Thai's members are expected to pick real-estate tycoon Srettha Thavisin as their candidate for prime minister in a parliamentary vote set for Tuesday.

He'll be seeking support from more than half of the 750-seats. The new coalition holds 314 in the Lower House.

But in the latest opinion poll, 64 percent of respondents say they do not want a government featuring Thailand's pro-military conservatives.

Familiar faces from the recent past are emerging amid all the unrest. Former leader Thaksin Shinawatra will likely return from exile on Tuesday. He was ousted in a military coup back in 2006.

He's affiliated with Pheu Thai, and local media say his negotiators may be asking the new coalition to grant him a pardon.