It is expected that the agenda item at the weekly Cabinet meeting will be proposed by Deputy Prime Minister and Defence Minister General Prawit Wongsuwan, although that cannot be confirmed.

Last week, Prime Minister General Prayut Chan-o-cha said the deal was settled in a “buy-two-get-three” way, plus services after the purchase, meaning the government would pay for two submarines and get the third one as “a free gift”.

The submarines should be worth the money spent on them, he said.

The details of the first instalment of the Yuan Class S26 T submarine is expected to be concluded on Tuesday, as the Budget Bureau announced that any proposal for a deal not exceeding Bt1 billion needs to be put before the Cabinet by this month.

The purchase, hyped up since the military-installed government took power in 2014, has been carried out amid criticism about the necessity of spending so much money given that Thailand has no maritime security threats.

But Prayut insisted the submarines were needed because the Kingdom’s small submarine fleet was decommissioned in 1951.