Prime Minister Prayut Chan-o-cha stood by the Defence Ministry's weapons procurement projects, saying they are essential to boosting national security, after the opposition took aim at the ministry's budget on Thursday.
On the third day of deliberation for next year's budget, Gen Prayut -- who is also serving as Defence Minister -- told parliament that the ministry has to ensure it is capable of dealing with any form of security threat despite its limited budget.
"We have to procure [weapons] when it is necessary. We can't afford to wait until the weapons in our arsenal expire before purchasing new ones," he said.
"Thailand does not receive assistance from anyone so we must rely on ourselves to bolster our defences," he said.
According to Deputy Defence Minister Chaichan Changmongkol, the ministry has been allocated 197.2 billion baht for the next fiscal year, down 4.37 billion baht from the budget in the previous fiscal year.
The PM jumped to the budget's defence after deputy Pheu Thai Party leader Yuttapong Charasathien took aim at military spending, saying a number of procurement projects lack transparency.
Mr Yuttapong said the navy requested a budget of 40.3 billion baht, which will be spent procuring a number of weapons systems, including the Chinese-made S26T Yuan-class submarine.
Mr Yuttapong, a staunch critic of the navy's plan to acquire submarines, again slammed the planned purchase, before reiterating his claim that the navy was duped into buying a submarine with no engines.
The Royal Thai Navy had previously countered the MP's claim, saying the navy has outlined its required engine specifications and China will have to honour the contract.
The navy will hold talks with China Shipbuilding & Offshore International Co (CSOC) next Thursday.
According to a source, the vice president of CSOC will meet navy chief of staff Adm Tharoengsak Sirisawat after Germany's MTU 396 refused to sell the engines to China as they are designated a military/defence item.
CSOC has asked the navy to alter the contract to allow the use of a Chinese-built alternative, such as the MWM 620, which it claims to be of the same standard, but the navy is standing by the terms of the original contract.
The submarine is due to be delivered in 2024.
During Thursday's debate, Mr Yuttapong also targeted the navy's planned purchase of three Israeli-made Hermes 900-model unmanned aircraft vehicles (UAVs), at 1.34 billion baht each. He said the Philippine air force purchased the same model for about 340 million baht each.
He also slammed the Royal Thai Air Force's planned procurement of F-35A fighter jets worth 2.7 billion baht each, saying the planes, with an operating cost of about 1.2 million baht an hour, are too expensive to run given the current economic circumstances.