A Move Forward Party (MFP) MP has warned the government to keep its hands off a bill seeking to liberalise the liquor industry amid reports of attempts to shoot it down in parliament.

The bill seeking to amend the Excise Tax Act, dubbed the "progressive liquor bill", was proposed by Taopiphop Limjittrakorn, an MFP MP for Bangkok.

Supporters said the bill will break the monopoly held by a few corporate distillers and allow small-scale producers to enter the market.

Mr Taopiphop on Wednesday sent an open letter to Prime Minister Prayut Chan-o-cha warning him to stay away from the bill.

He also accused "the three brothers in arms", a reference to Prime Minister Prayut, Deputy Prime Minister Prawit Wongsuwon, and Interior Minister Anupong Paojinda, of being involved in such a move.

"There has been talk about the trio trying to shoot down the bill. I am not surprised," he wrote.

"If the trio claim that alcoholic drinks are harmful to the health of the public, they should end production by all major distillers and ban consumption altogether.

"Claims [the bill's passage would lead to] the proliferation of substandard drinks made by small-scale producers are unwarranted."

A government source confirmed that Gen Prayut met with Gen Prawit, Gen Anupong and leaders of coalition parties to discuss the bill. They agreed that they did not want the bill to pass out of concern about a lack of quality controls if it was enacted, the source said.

However, a deputy government spokeswoman yesterday said claims that Gen Prayut was behind the move to shoot down the bill were baseless.