Originated as the left faction of the official Arab Socialist Union (ASU).
When Anwar al-Sadat dissolved the ASU in 1976, the National Progressive Unionist Party (NPUP) emerged as the official left opposition party. A coalition of leftist forces, including Nasserists and Marxists, the NPUP under the leadership of Khalid Muhyi al-Din, formerly a member of the Free Officers, has played the role of active and vocal opposition in the People's Assembly.
— RAYMOND WILLIAM BAKER




