Future Forward Party spokeswoman and MP Pannika Wanich must account for her damning criticism of the constitution, Deputy Prime Minister Prawit Wongsuwon demanded on Monday.
The deputy prime minister was referring to comments made by Ms Pannika at a public forum in the opposition's campaign for a charter rewrite in the northeastern province of Maha Sarakham on Sunday.
Ms Pannika was quoted as saying that the entire charter must be rewritten because every section was heng suay -- good for nothing.
Gen Prawit said that even though charter amendment is included in the government policy manifesto, the issue is parliament's affair and political parties would have to handle it.
Ms Pannika on Monday defended herself, saying she had explained in detail at the forum why she held such an opinion. She insisted the origins of the charter were unjust and lacked public participation.
She said more than 200 people were detained for violating the coup-makers' ban on political gatherings as they campaigned against the charter prior to the public referendum. The legitimacy of the 21-member Constitutional Drafting Committee was also questionable since it was handpicked by the coup leader, she said.
"I'm stressing that the problem isn't with the content in each section. What I mean is that its origin is illegitimate, so the charter is illegitimate," she said, adding that the FFP would nevertheless resort to constitutional channels to pursue the charter rewrite.
Meanwhile, deputy Senate speaker Supachai Somcharoen said the Senate has yet to select amendments for consideration after the government and opposition MPs proposed separate motions to set up a committee to study constitutional changes. He also denied that senators were waiting for a signal from the government about how to proceed.