Pheu Thai MP for Chiang Rai Samart Kaewmeechai yesterday remained adamant that his bid to oust Constitution Court judges is the right thing to do.
Mr Samart said he would spearhead the impeachment bid even though its chances of success were slim.
The Pheu Thai Party has distanced itself from Mr Samart's move.
Party spokesman Prompong Nopparit said on Sunday the impeachment move did not represent a party decision, but was at the discretion of individual MPs.
Mr Samart said he was not worried about whether the impeachment bid would succeed as MPs merely wanted to maintain a balance between legislative and judicial powers.
An ouster bid requires the support of three-fifths of senators. Half of the upper house is filled with appointed senators known to be critical of the government's charter amendment attempts.
The impeachment campaign against the charter court judges came after the court decided to accept for consideration a petition by Senator Somchai Sawaengkarn asking it to rule on the legality of the move by 312 MPs and senators to amend Section 68 of constitution.
Mr Samart believes the court did not have the authority to agree to consider the petition. However, Mr Samart said he would first submit an open letter denouncing the court's decision before kicking off the sign-up campaign. "The letter is being drafted. We'll see how the charter court responds to it," he said.
An impeachment bid would be submitted to the Senate speaker who would then forward it to the National Anti-Corruption Commission (NACC) for an inquiry. The NACC would send back its findings to the Senate for a vote.
Senate speaker Nikhom Wairatpanich yesterday said the Senate will ask the charter court to extend its deadline for clarification on the constitutional amendment bills by 30 days.
MPs and senators who voted for the bills were asked to counter Sen Somchai's petition by April 26. About 60 senators signed up in support of the charter amendments. Section 68 allows the public to complain directly to the court about moves against the constitutional monarchy or attempts to grab power unconstitutionally.