Grand Ayatollah Haeri (mentor of Muqtada As-Sadr) breaks with him. From his site (my translation):
"Question: Is Sayyid Muqtada As-Sadr your representative?
Answer: Sayyid Muqtada does not consult with us, and does not coordinate with us, and accordingly does not represent us and is not our [official] agent. Our office in Iraq represents us, and is currently under the supervision of his excellency Hujjat Al-Islam and Muslims Shaykh Qasim Al-Asadi, known as Abi Hajir, may God preserve him."