CAIRO (Reuters) - A leading Egyptian Islamic scholar brought together rival politicians on Thursday in a bid to ease a crisis that has triggered street violence, killing more than 50 people, saying dialogue was the only way to resolve differences.

Sheikh Ahmed al-Tayyeb, the head of al-Azhar mosque and university, brought together members of the Muslim Brotherhood - the Islamist group that propelled President Mohamed Mursi to power - with the president's most vocal opponents, including liberal politician Mohamed ElBaradei.

Reading from a document, Sheikh al-Tayyeb said national dialogue "in which all elements of Egyptian society participate, without any exclusion, is the only tool to resolve any problems or differences". He said violence and bloodshed was forbidden.

(Writing by Tom Perry; Editing by Janet Lawrence)