The ruling Pheu Thai Party has admitted it may have to thrash out differences with coalition partners before it can press on with its plan to rewrite the charter.
Somkid Chueakong, the prime minister's secretary-general, made the remarks as he attended an event to mark the 51st anniversary of the popular uprising on Oct 14, 1973, at a memorial on Ratchadamnoen Klang Avenue on Monday.
Mr Somkid said Pheu Thai is committed to promoting democracy. Still, it also has to work with other coalition partners, and sometimes, issues, such as a referendum on charter amendments, can hit hurdles.
"We admit there are some obstacles, and we are trying to iron them out," Mr Somkid said.
One such hurdle was the Senate moving to reinstate a tougher requirement for referenda to pass -- the so-called double majority rule.
It says that for the result to be binding, at least half of all eligible voters must cast their votes, and the winning outcome must be supported by at least half of the voters who turn up at polling stations.
However, on Oct 9, the House voted 348 to zero to reject the Senate's push to reinstate the double majority rule. After that decision, a joint House-Senate committee will be formed to iron out differences.
Before the vote, Pheu Thai and the main opposition People's Party (PP) affirmed the Lower House's resolution to switch to the simple majority rule. They pointed to the risk of a delay if the double-majority rule went unamended.
But the Bhumjaithai Party did not join the Lower House vote to reject the Senate's decision to retain the double-majority clause in the referendum bill for the sake of being thorough, said the party's leader, Anutin Charnvirakul.
Mr Anutin, also a deputy prime minister and interior minister, said Bhumjaithai was all ears to opinions from the Senate and related parties, but the process needs care.
Despite the difference in opinion, the Pheu Thai Party is confident that a referendum will take place early next year as planned.
Pheu Thai secretary-general Sorawong Thienthong previously said the party is committed to holding a referendum early in 2025. The first step is ensuring the amended bill passes parliament in the next few months.