A successful charter rewrite requires people to be aware of the need to push for change that can achieve a balance between the powers of the state and the people, a forum was told.
The forum organised by the Future Forward Party (FFP) in Ang Thong province on Sunday was attended by politicians and academics.
Watana Muangsook, a member of the main opposition Pheu Thai Party, said the charter has to be amended in a way that does not incite conflict.
Members of parliament must agree to amend the constitution and redistribute power to people. At the same time, people must have a say in electing members of the charter redrafting committee.
The constitution must be reviewed in its entirety, not amended in certain sections, and approved by the people.
Chirmsak Pinthong, a former senator, said a good constitution is one that is conducive to increasing both the powers of the state and the people.
The current constitution, however, downplays the need for balance as it gives more power to the state and reduces the power of the people.
A glaring example of that is the selection of 250 senators by the now-defunct National Council for Peace and Order.
The charter was written to give senators the added power to endorse the coup-maker, Gen Prayut Chan-o-cha, as prime minister while the process is not connected in any way to the people, he said.
Mr Chirmsak said that while he supported an election of senators, it should not take the form of a general election; otherwise it would produce another crop of MPs, causing parliament to have two indistinguishable Houses.
In fact, senators should represent professional groups and act as a "mature chamber" attending mainly to legislative screening and monitoring independent agencies.
Pibhob Dhongchai, adviser to the Campaign for Popular Democracy (CPD), told the forum he believed the charter is not impossible to amend, despite a popular perception that it was designed to be almost impervious to a rewrite.
A panel has been appointed by the House of Representatives to study the charter amendments. It is chaired by Pirapan Salirathavibhaga, adviser to the prime minister.
Changing the charter requires the right strategy and maneuverability, according to Mr Pibhob.
He advised the FFP, which is advocating charter change, to ramp up its efforts for the amendments in parliament while the civic sector must educate people and make them realise there is a need to improve or rewrite the constitution.