Abu Ubaida, whose alleged real name is Hudayfa Samir Abdallah al-Kahlout, is a Palestinian militant who has been the spokesperson for the Ezzedeen al-Qassam Brigades, the military wing of Hamas, since at least 2007. From Wikipedia
Hamas has warned it may withdraw its interim-truce offer unless negotiators resolve deadlocks over Israeli troop redeployment in Gaza.