The charter should be amended section by section to avoid having to conduct a referendum, as the focus should be on forming an assembly to redraft the constitution, according to legal experts.
Wissanu Krea-ngam, a former deputy prime minister and prominent legal expert, said the referendum presents what look to be insurmountable legal and technical hurdles in passing a wholesale constitutional amendment within the current term of the House of Representatives.
The bill to prepare the groundwork for a referendum appears to be giving lawmakers more trouble than they need, he pointed out.
At least three referendums, as ruled by the Constitutional Court, must be organised with an approval vote before major changes can be made to the charter.
With the House's term set to expire in less than three years, concern is growing that the process of arranging the referendums that mandate sweeping charter amendment and rewriting the constitution cannot be completed in time.
Mr Wissanu said the best option was to rewrite the charter section by section, which does not require a referendum. However, it stipulates which sections or chapters in the charter necessitate a referendum if they were to be modified.
"If we go down the path of a referendum, we are bound to run into a debate about how many must conducted.
"Be specific and rewrite the sections that are urgent or necessary and keep well clear of the referendum-required sections. If this is done, the charter amendment might be finished in time," he said.
Nikorn Chamnong, a list MP of the Chartthaipattana Party and secretary of the House-Senate referendum committee said the window was closing on organising two referendums and amending the charter within the tenure of the current House.
Two referendums would defy the Constitutional Court ruling, and for that reason, he believed few lawmakers would support it.
He said a viable alternative was for a bill to be tabled to amend Section 256, paving the way for a constitution-rewriting assembly to be set up to accommodate section-by-section changes. The bill could be submitted to parliament by January and take effect by March 2027, he said.