Prime Minister Prayut Chan-o-cha should take responsibility for the row that erupted after the government suspended operations at a gold mine four years ago, says the Pheu Thai Party.
Its call comes ahead of an expected decision by an international arbitrator on Oct 31, on a legal dispute between an Australian-based company operating the gold mine through a sister company in Thailand, and the government.
The suspended mine was operated by Akara Resources, whose parent firm, Kingsgate, is engaged in the legal tussle that has ended up in arbitration.
Akara's Chatree gold mine in Phichit was closed by a court order when villagers complained about the environmental and health impacts.
The order came after the now-defunct National Council for Peace and Order invoked Section 44 of the interim charter to suspend mining at the site on Jan 1, 2017.
Akara, however, disputed the claims, insisting it had complied with environmental protection regulations.
The Prayut government has reportedly forked out a large sum in defending its decision during the arbitration process.
If Thailand loses the case, the entire country will have to pay compensation to the winner, Pheu Thai said as it called on the public to demand the PM take responsibility.
It is unclear how much an unfavourable arbitration decision could cost the state, but at one point the Australia-based company was seeking 30 billion baht in compensation.
Government spokesman Thanakorn Wangboonkongchana said Pheu Thai should wait for the results of the arbitration instead of trying to mislead the public by speculating on the outcome.
The government insists on following international rules in its legal battle with Kingsgate, the major shareholder in Akara, while at the same time agreeing to negotiations to settle the dispute, he said.
Gen Prayut did not abuse his Section 44 power to shut down the gold mine as claimed, but used it to suspend the renewal of expired mining concessions, the spokesman said.