Suthep says the meeting shows he has public backing of the military. But a statement from the supreme commander says the meeting is a "public forum" that includes civic groups.
On the face of it, Suthep's bid to upend Thailand's current political order looks far-fetched.
The former deputy prime minister has called for a parallel government and a volunteer police force. He wants Yingluck arrested for insurrection and has ordered civil servants and the army to report to him, not the government.