If the draft charter is rejected by the NRC on Sunday, a new draft must be written by a new panel of drafters.
If the draft is accepted but there is nothing in it to guard against renewed conflicts, there will be problems in the future, Gen Prayut said.
He made the comment as NRC members appear to be split over the draft.
NRC member Amorn Wanichwiwat said the vote was too close to call as several NRC members, particularly those who represent local administrations who previously supported the draft, are said to have had a change of heart. According to Mr Amorn, the no-vote is close to 130.