ACT secretary-general Mana Nimitmongkol said the Budget Bureau, the Office of the Auditor-General and the National Anti-Corruption Commission should launch an investigation before damage is inflicted.

“I suspect that the project will be carried out in favour of private enterprises at the expense of the nation,” he said.

Mana spoke out after assistant government spokesman Colonel Atisit Chaiyanuwat disclosed that the Cabinet had exempted the project from bidding to speed up the project.

“Bidding should take place to ensure transparency,” he said.

Speaking separately, Atisit said private investors would fund the tower project.

He also backtracked from his earlier statement that the 459-metre-high tower would cost Bt7.6 billion, bringing that figure down to Bt4.6 billion

Atisit also said the project only needed Cabinet approval because it would be developed on a plot of land belonging to the Finance Ministry’s Treasury Department. Located in Bangkok’s Klong San district, the plot is located on the Chao Phraya River.

“The 30-year land lease comes with a rental fee of Bt198 million,” Atisit said.

Ekniti Nitithanprapas, who heads the State Enterprise Policy Office, insisted that the tower project had won approval from relevant authorities and proceeded in line with regulations.

“We can decide on whether to require bidding,” he said.

Prime Minister General Prayut Chan-o-cha also stood by the project.

“The tower will be a new landmark in Bangkok. It will house a museum about Thailand’s history and monarchy,” he said.

Chatri Prakitnonthakan, a lecturer at the Faculty of Architecture Silpakorn University, said the tower project showed a lack of transparency on many levels.

“In this project, developers get rights to develop this public land without passing the proper procedures of official bidding. In addition, these investors also pay a rent to the government at a very cheap rate of around Bt6 million per year, despite this land having very high value,” Chatri said.

He also commented on the lack of public involvement in the “top-down” project. Being a landmark built on public land, citizens should be able to play a part at the design stage, he said.