Mr Parinya told a press conference at parliament that groups of monks had turned up at public hearings on the draft constitution held in northern and northeastern provinces.
During the sessions, those monks called for Buddhism to be declared in the new charter as the state religion, and handed out leaflets denouncing opponents of the move as people who were trying to ruin national integrity, religion and the monarchy, he said.
The monks also told people at the hearings to raise their hands in support of declaring Buddhism the state religion. Afterwards, they left the meeting rooms without showing interest in other contents of the draft charter, he said.
''At some sessions the monks ... reportedly gave the villagers who opposed their stance a hard stare. So I don't think opinions on the issue should be gathered as statistics for reporting to the Constitution Drafting Assembly,'' he said.
Monks should carefully consider if such campaigns went against the rule of them staying out of politics, he added.
Another CDA member, Somyos Somwiwatanachai, remarked that such campaigns might cause rifts among Buddhists.