The House of Representatives on Wednesday voted 262:162 to reject a motion asking the cabinet to hold a public referendum on a charter rewrite.
The vote came after the MPs spent more than four hours debating the motion proposed by the main opposition Move Forward Party (MFP).
A total of 262 rejected the motion, while 162 others voted in its favour with six abstentions.
Pheu Thai list-MP Chaturon Chaisaeng said the ruling party was not opposed to the MFP's motion because charter amendments required cooperation from all sides to succeed.
However, he said the referendum law needs to be amended first because its requirements make it extremely difficult for a charter rewrite proposal to be adopted.
Section 13 of the referendum law says the referendum is considered passed when two requirements are met: when more than half of voters approve it and when more than half of the eligible voters participate in the referendum.
"The requirements make it difficult for the charter rewrite referendum to pass. Unless the law is revised, there is a great risk the referendum will not pass," he said.
MFP MP Parit Wacharasindhu told the House that the party did not care how long the government-appointed panel on the design of the referendum would take to study the issue.
He said the MFP's concern involved the questions to be asked at the referendum and noted the MFP MPs preferred giving their opinions on the charter rewrite in parliament.
Meanwhile, the government is set to gather public opinions on the planned referendum on a constitutional amendment from various groups.
The sub-panels set up by the government committee studying a referendum on amending the charter met on Wednesday to discuss their tasks.
One sub-panel is gauging the public's opinion on the matter and the other is responsible for drawing up a guideline for a referendum.
Chanin Rungthanakiat, a Pheu Thai MP who sits on the committee drawing up the guideline, said opinions will be gathered from three groups.
The first group comprises MPs, senators and members of various House committees.
The other two groups are students, members of the public, civic groups, the media and the business sector.
The sub-panels are reportedly expected to wrap up their assignments around the end of the year.