Disagreements surrounding the referendum bill may be settled as early as tomorrow, with opposing parties set to strike a deal on a "one and a half" majority rule as an alternative to the double majority requirement to pass a referendum.
Sources say the details will be known when members of the House-Senate committee on referendums meet on Wednesday to thrash out their differences over the changes to the bill.
Nikorn Chamnong, secretary of the House-Senate referendum committee, said the committee would invite Ratthapol Pakdeephum, chairman of Thailand Post, and Election Commission secretary-general Sawang Boonmee to provide their input on voting by mail.
The joint committee was formed after the Senate reversed the House's decision to do away with the double majority requirement and opt for a simple majority to ease the passage of referendums on constitutional amendment.
The double majority rule refers to a requirement outlined in the Referendum Act, which specifies two conditions before a referendum result can be considered binding. First, more than 50% of eligible voters must have participated in the referendum, and the majority of those who cast votes must approve it.
Under the simple majority rule, the motion must be backed by more than half of the votes cast for a referendum to be adopted.
Mr Nikorn hoped a solution could be reached at Wednesday's meeting.
Any decision emerging from the joint panel will be tabled for parliament's approval at the next parliament session, which will be reconvened next month.
"I'm all for a middle path," he said.
Mr Nikorn proposed a "one and a half" majority rule, in which the motion backed by more than 50% of eligible votes in a referendum is retained, but the motion does not necessarily have to be backed by a majority.
He defended the option as feasible, saying it had been studied and mentioned in a report on charter amendments considered by the cabinet back in April.
Meanwhile, Pheu Thai Party list MP Prayut Siripanich, who is also member of the joint committee, disagreed with the "one and a half" majority rule proposal, saying it is almost identical to the double majority rule.