The Move Forward and Pheu Thai parties have joined a growing call by activists against a bill to keep activities of non-governmental organisations (NGOs) in check.
Pheu Thai spokeswoman Theerarat Samrejvanich told the parliament on Thursday the government should reconsider a push for the bill on the operations of nonprofit organisations (NPO bill) to become law as it would curb freedom of expression.
She warned of growing protests if the government ignores the call by the protesters.
On Wednesday, Move Forward leader Pita Limjaroenrat made a promise to a group of protesters that his party would vote against the bill once it is put on agenda.
"If the bill is tabled for consideration by parliament, the Move Forward Partry will definitely vote against it," Mr Pita said.
The NPO bill is in the stage of seeking public opinion. The process is undertaken by the Social Development and Human Security Ministry after the cabinet agreed in principle in a meeting in January. Once the process is complete, it has to receive cabinet approval before the bill can go before parliament for deliberation.
Two of the controversial issues in the bill are to order NGOs to disclose their sources of funding and a clause saying their activities must not threaten national security and law and order.
According to some critics, the NPO bill has been designed to curb NGO activities and silence anti-government voices. They consider the bill a product of the now-defunct National Council for Peace and Order, which staged the coup in 2014.
The bill has faced opposition from almost 2,000 NGOs across the country and they vowed action would be taken against it.
In January, government spokesman Thanakorn Wangboonkongchana defended the bill, saying it was conceived in the best interests of the public. Its scrutiny was open and transparent since it will be subject to public opinion.
Protesters against the bill had camped out outside the United Nations compound on Ratchadamnoen Avenue on Monday and paraded to Government House on Tuesday to petition the government to scrap the bill. Their petition was sent to Prime Minister's Office Minister Anucha Nakasai.