BANGKOK Thailand's Pheu Thai Party will drop the army-backed Palang Pracharat Party from its coalition when it forms the next government, an official said on Tuesday, signalling fissures in an awkward alliance with its bitter rivals in the military.

The decision comes after Pheu Thai lawmakers expressed outrage that Palang Pracharat's leader, Prawit Wongsuwon, a general who was involved in coups against Pheu Thai and its predecessor, failed to show up for a parliamentary vote to approve new Prime Minister Paetongtarn Shinawatra.

"The Palang Pracharat Party will not be involved in the formation of the government," Sorawong Thienthong, Pheu Thai secretary general, told Reuters.

Pheu Thai sprang a surprise last year when it reneged on its promise not to work with military-backed parties by allowing Palang Pracharat, which has 40 seats, to join its 11-party coalition.

Its influential leader Prawit, a former army chief with powerful connections in Thailand's royalist establishment, has had a turbulent relationship with Pheu Thai's billionaire founders, the politically dominant Shinawatra family, whose governments he twice helped overthrow.

Sorawong shrugged off the loss of seats and said Pheu Thai's coalition could still expect to have more than 300 of the 500 parliamentary seats.

He said Pheu Thai would bring in a splinter faction from Palang Pracharat, which has been fraught with internal discord, and would also team up with its erstwhile but now diminished rival, the Democrat Party, which has 25 seats.

Earlier this month, Paetongtarn, the 38-year-old daughter of influential heavyweight Thaksin Shinawatra, won a parliamentary vote to become Thailand's youngest premier, just days after ally Srettha Thavisin was dismissed as prime minister by a court.

Paetongtarn, the third Shinawatra to lead Thailand, is now in the process of forming her cabinet and is expected to present her government's policies by the middle of next month.

Palang Pracharat's spokesperson Piya Tavichai said Pheu Thai had not notified them of the decision and had broken their agreement.

"All Palang Pracharat Party lawmakers, except our leader who was caught up elsewhere, all voted for the prime minister," Piya said. "This is going back on their promise and it lacks manners."

  - Reuters