Prime Minister Anutin Charnvirakul and Pheu Thai leader Julapun Amornvivat put on a public display of unity on Tuesday, dismissing speculation the ruling coalition could fracture ahead of an expected no-confidence debate later this year.

The show of solidarity came amid persistent rumours that Pheu Thai could join forces with the Klatham Party and the opposition People's Party (PP) in a parliamentary realignment that could topple the government.

Speaking at Government House, Mr Anutin, who also serves as interior minister and leads the Bhumjaithai Party (BJT), was asked about comments made a day earlier by Capt Thamanat Prompow, leader of the opposition Klatham Party, suggesting Klatham had put past political conflicts behind him.

"Not yet. I got home late last night," Mr Anutin joked when asked whether he had heard Capt Thamanat's remarks.

Asked about speculation over a "red-green-orange" political alliance -- referring to Pheu Thai, Klatham and PP respectively -- Mr Anutin paused before responding humorously.

"Red and green? Just add shaved ice and pour Carnation condensed milk over it," he said with a thumbs-up gesture, likening the colour combination to a popular Thai dessert.

When reporters asked whether he had already discussed the rumours with Pheu Thai, Mr Anutin pointed towards Labour Minister Julapun Amornvivat, Pheu Thai leader, who was standing nearby.

"There he is," Mr Anutin said before walking over to Mr Julapun.

Asked whether the "blue" and "red" coalition remained intact without the need for another political colour, the two leaders smiled.

"It's a perfect blend," Mr Julapun replied.

As they walked towards the Thai Khu Fah Building, reporters again asked whether their parties were still working closely together. In response, Mr Anutin embraced Mr Julapun in front of cameras, underscoring the coalition's united front.

The public display came as speculation continues over the stability of the BJT-Pheu Thai coalition ahead of parliament's next session, when PP is expected to file a no-confidence motion targeting Mr Anutin and his cabinet.

The rumours have suggested that Pheu Thai could vote against Mr Anutin during the debate, paving the way for the formation of a new coalition government involving Klatham and PP.

However, political observers have questioned the feasibility of such a scenario, noting the ideological differences between PP and Klatham, as well as repeated denials from all parties involved.

Meanwhile, Natural Resources and Environment Minister Suchart Chomklin, a senior BJT figure, dismissed the reports as routine speculation. "It is just political colour," Mr Suchart told reporters.

"It happens every time. When the government has largely dealt with the country's pressing problems, political rumours emerge to create excitement."

The latest rumours follow claims circulating this week of a so-called "red-green-orange" alliance.

On Monday, Capt Thamanat denied reports he had secretly travelled overseas to negotiate a new governing coalition or met former prime minister Thaksin Shinawatra.