The Pheu Thai Party has tabled a bill to change a constitutional provision governing a referendum for charter amendment to parliament, deputy party leader Chusak Sirinil said.
He said that the charter amendment bill signed by 122 Pheu Thai MPs was submitted to parliament president Wan Muhamad Noor Matha last Thursday.
But if the parliament president refuses to put the bill on parliament's agenda and says the bill attempts to write a new constitution which requires a referendum to be held first, this would lead to a conflict over parliament's power as Pheu Thai believes that lawmakers possess full authority to amend the charter, Mr Chusak.
If the parliament president refuses, Pheu Thai MPs will ask the Constitutional Court to rule on whether MPs have such authority, Mr Chusak said, adding that the party is also seeking the court's ruling on how many referendums on charter amendment should be held.
The proposal to revise the military-sponsored 2017 constitution, which was one of the ruling party's election pledges, is listed as a priority issue for the coalition government.
The referendum is a thorny issue thanks to a 2021 Constitutional Court ruling that the public must approve any move to amend the entire charter. If a rewrite is approved, another referendum must be held to approve the content.
The government previously set up a committee to draw up new guidelines for holding a referendum to find common ground on how the 2017 constitution should be amended.
It is chaired by Deputy Prime Minister and Commerce Minister Phumtham Wechayachai.
Mr Phumtham's panel recently approved a proposal to hold three charter amendment referendums and decided that only one question would be asked in the first one.
The question will be whether or not voters agree with the proposal to amend the constitution, except for Chapters 1 and 2, which deal with general provisions and the King, respectively.
The three referenda will cost 10.5 billion baht, he said.
However, Mr Chusak said on Monday that Pheu Thai's working panel on charter amendment has agreed that only two referendums should be held as this will help save money and time.