The Senate should not take part in a study of the proposed constitutional amendment as the matter should be left to the MPs, Sen Gen Somjate Boonthanom said on Saturday.
Gen Somjate rejected media reports he would be among six senators who would be chosen by the government to sit on a committee on the charter amendment study.
Gen Somjate said he would not join the committee as he saw no need to amend the constitution at the moment. As for the other senators, they can use their discretion to decide whether to join the committee.
''I think senators should not take part because it [constitutional amendment] is the business of the House. It should be left to MPs who want to amend the charter to discuss the matter."
Deputy Prime Minister Wissanu Krea-ngam had earlier said no cabinet ministers would take part in a study of the proposed constitutional amendments.
Government and opposition whips had originally decided there will be 49 members; 18 representing the coalition government, 19 from the opposition, and 12 cabinet ministers.
However, the inclusion of cabinet ministers was dropped because it was deemed they may not have enough time to attend the study committee meetings, according to Mr Wissanu.
The exclusion of ministers would leave 12 seats vacant, six of which are expected to be filled by senators, members of independent agencies, and the government's legal experts while the other six seats will be taken up by individuals decided by the government whip.
Mr Wissanu agreed senators should have a role to play on the committee as designing charter changes and approving them would be difficult without the Upper House's help.
Sen Wanchai Sornsiri said that demands for a constitutional amendment have come from only a group of politicians so far and not the public.
Mr Wanchai said those who have campaigned to rewrite the constitution are politicians who lost in the general election and want to seek ''a rematch'' and hope to come to power.
Digital Economy and Society Minister Buddhipongse Punnakanta, who is a key figure of the ruling Palang Pracharath Party (PPRP), said the party is approaching experts from outside the party to nominate for the committee chairman's post. The party will then meet to choose the most qualified candidate for the post, Mr Buddhipongse said.
Education Minister and PPRP deputy leader Nataphol Teepsuwan had earlier insisted that the chairman of a House committee to study constitutional amendments should come from the PPRP.