
"We view the draft constitution as undemocratic and call on people to reject it at a referendum," Chaturon said.
He blamed authorities for misleading voters into believing they could cast votes of approval only.
He alleged junta opponents were denied access to news-media outlets to air their views.
The campaign slogan is "Vote No to the 2007 Constitution and Demand the Return of the 1997 Constitution".
Surapong Suebwonglee is in charge of publicity and said he headed a working group publicising the campaign, promoting awareness of the slogan and spelling out reasons why the charter should be rejected.