Cracks on the runway, corruption allegations and now safety issues - Bangkok's new airport has suffered blow after blow since its swanky opening, but analysts say the public hammering could be a ploy to discredit the ousted premier.

Suvarnabhumi Airport, built at a cost of US$3 billion, appears an easy target for Thaksin Shinawatra's critics, especially as he made the scheme a personal project, once camping at the building site in a show of support.

Taking on a project that had been in the pipeline for 40 years, he raced to open the airport before many experts believed it was ready.

When the new hub finally opened to much fanfare September 28 last year, the twice-elected premier had been toppled by the military in a bloodless coup just over a week earlier.

Since then there has been a catalog of complaints, culminating last week with news the transport ministry was considering whether to move flights back to the old Don Muang airport because of about 100 cracks on runways and taxiways.

"Since Thaksin had pushed the airport very strongly ... it would be very nice for the military regime to say `see, that was all just public relations,"' said Michael Nelson, politics lecturer at Bangkok's Chulalongkorn University.

"It would be a nice thing to show the world that in fact, behind the scenes, it was all cronyism and corruption."

The military justified their takeover saying democracy was being undermined by Thaksin, but they have yet to uncover any hard evidence of graft.

"They want to discredit him as much as they can, even if they can't nail him for anything concrete," Nelson said.

The problem was compounded when Thailand's aviation authority declined to renew an international safety certificate for Suvarnabhumi.

Political analyst Thitinan Pongsudhirak, also of Chulalongkorn, agreed that focusing on the problems would embarrass Thaksin, now living in exile.

"This was Thaksin's pet project, his showcase project," he said. "It has blown up in his face."

But Thitinan said the problems appear to be genuine.

"No one denies there are serious construction problems ... I don't think the military is digging it up just to discredit Thaksin," he said.

Thitinan said the move to investigate the airport problems is part of a broader push by the military to show its teeth after accusations they are being too soft on Thaksin's policies.

"The military, finally after four months, is getting tough," he said.