The Election Commission (EC) has estimated that organising a referendum would cost 3 billion baht, up from the 2.7 billion baht price tag in the previous round, largely due to an increase in voters.
The EC has been meeting a government panel to study the charter-amendment referendum.
The agency steered clear of political questions put forth at the meeting, particularly those regarding any changes to the referendum law as advocated by some quarters, according to Sawang Boonmee, the EC secretary-general.
The changes being pushed include lowering the minimum votes required for passing a referendum. Mr Sawang said the EC focussed on how the referendum would be held.
"We are also focusing on whether there will be a referendum and if so when it can be held. We're bound by duty to put one together if need be," Mr Sawang said. He said, however, the EC will need more money than in the previous referendum to finance a fresh round.
A referendum is estimated to cost at least 3 billion baht, up from 2.7 billion baht spent on the previous referendum in which the majority of voters approving the current charter. The EC attributes the steeper cost to a higher number of voters, new legal regulations, and inflation.
Meanwhile, Deputy Prime Minister Phumtham Wechayachai, who leads the government committee studying a referendum on constitutional amendments, said on Saturday a sub-panel on public opinions has made headway. However, it has yet to hear from ethnic groups in the North and Muslim communities in the South.
Feedback will also be gathered from MPs and senators when parliament reconvenes. "At this point the task of guaging public opinion will be concluded," he said.
The result of the hearing will be compiled by the sub-panel and presented to the main committee and later the cabinet. Another sub-panel studying referendum methods was split over Section 256 of the constitution regarding who and how members of the charter-drafting assembly will be selected.
"Despite the differences, we want the charter amendment to reflect the wishes of the people and modernise the constitution," the deputy premier said.
Last week, Nikorn Chamnong, head of the hearing sub-panel, admitted he was concerned the Referendum Act might complicate the charter amendment process.
He conveyed his concern specifically on the requirements that over 50% of citizens eligible must have voted and that a majority of those who cast votes must approve it.
He said the so-called double-majority will be difficult to achieve, explaining that under a simple majority rule, at least 26 million eligible voters must cast their votes for the result of the referendum to be considered binding.
With a double-majority requirement, at least 13 million must have voted to approve the amendment itself for the result to be legally binding.