Criticism is mounting against parliament's request for a billion baht in additional budget for renovations, despite the new chambers only opening last year.
Critics, including several MPs from the People's Party, slammed the decision ahead of deliberating the 3.78-trillion-baht 2026 budget.
The bill was approved by the cabinet during its mobile meeting in Nakhon Phanom on April 29.
Among a number of contentious proposals are requests for 113 million baht to fund the refurbishment of parliament's Sala Kaeo (Crystal Pavilion), and a 180-million-baht sum to install a 4D cinema within the complex.
Parliament has defended the initiative, saying the "cinema" will, in fact, be an information room for visitors.
The bill also seeks 118 million baht to upgrade the lighting in seminar rooms on floors B1 and B2; 117 million baht to refurbish the parliamentary kitchen area and repurpose part of it as a recreation room; and another 99-million-baht request to upgrade the sound and video systems in parliament's 1,500-seat conference room.
Deliberations of the budget bill for the 2026 fiscal year will be held on May 28-30.
Wisut Chainarun, the chief government whip and a Pheu Thai Party list MP, said on Monday that the government will slash unnecessary budget allocations and Pheu Thai MPs will scrutinise the bill to ensure it benefits the people.
Asked about parliament's budget request for renovations, he said that priority should be given to stimulating the economy to ease hardship.
Both government and opposition MPs must work together to scrutinise and reject any projects that do not benefit the public and do not stimulate the economy, he said.
Pheu Thai MPs will hold a meeting on May 13 to discuss preparations for the budget bill debate, with working panels to be set up to study various aspects of the bill including how much is to be set aside for the economy, education and public health as they gather information to be used for the debate.
Sirikanya Tansakun, an MP and deputy leader of the opposition People's Party (PP), said the government had failed to show restraint and had neglected to revise its spending plan, preferring to shift the burden of slashing unnecessary budget requests onto other parties.
She said the government should ask for the bill to be returned for further revisions before resubmitting it to parliament.
A House committee on political development, mass communications and public participation, led by Parit Wacharasindhu, a PP MP, is also looking into the rationale behind parliament lobbying for such a huge budget for renovations despite the new building only having been fully completed and open for official use last year.
Thanakorn Wangboonkongchana, deputy leader of the United Thai Nation Party, a coalition government member, also joined calls for more clarity and transparency regarding parliament's seemingly unnecessary request for funding for renovation and construction. "A lack of clear information and transparency will ruin parliament's credibility," he said.