Salah al-Shanfarah, Dr Nasser al-Khabaji, and Muhsin Basarah have been boycotting parliament in recent weeks in protest against government action in the south.
Posters of Bashar al-Assad, who succeeded his father Hafez in 2000, are everywhere on Jabal Muhsin, while rebel Free Syrian Army flags outnumber Lebanese ones in the Sunni areas nearby.