Campaigns against the draft constitution will be banned except in debates held by the Election Commission, Deputy Prime Minister Wissanu Krea-ngam said.
"Organisers will hold such debates at their own risks. We have several laws to deal with them such as the laws on defamation and public assembly," he said.
The EC is drafting a law governing the referendum based on election laws and the 2007 referendum law.
The National Council for Peace and Order (NCPO) and the cabinet on Tuesday agreed to amend the 2014 interim charter to clarify the criteria on the "majority" of voters.
Section 37 of the interim charter says after the draft is finished, it will be put to a referendum and must be endorsed by "the majority of voters", instead of "the majority of voters who cast ballots in the referendum" as written in previous charters.
"The clause will be changed so that it's clear the draft will be endorsed by the majority of cast ballots. The 'no' votes, abstentions or damaged tickets will not be counted," he said.
The voting age will be set at 18 or more on the referendum date, he added.
The meeting also got rid of the requirement that copies of the draft be sent to at least 80% of voters, reasoning there were other ways to access them.
"The Constitution Drafting Committee (CDC) will publish a handbook with easy-to-understand infographics to be handed out and put on websites and in advertisements and announcements."
The National Legislative Assembly can also add other questions to ask voters by submitting them to the Election Commission without having to tell the cabinet, Mr Wissanu said.
The questions must be ready within 15 days from the date the final draft is unveiled, or March 29.
On what they plan to do if the draft is voted down, the deputy prime minister said the meeting had not discussed this.
"We thought it was for the next stage. If the draft is endorsed, there no need to talk about it. But if it is rejected, we'll know what to do.
"Talking about it now may cause prejudice. Besides, we haven't decided on the best course of action."
