(CNN) -- One of the eight candidates in Iran's upcoming presidential election has dropped out of the race, Iranian media outlets reported Monday.
He is Gholam-Ali Haddad-Adel, 68, a conservative and former speaker of the parliament. His daughter is married to Ayatollah Khamenei's son. It was not immediately known why he made the move. The election is scheduled to take place Friday.
Haddad-Adel completed a doctorate in philosophy at the University of Tehran in 1975 and holds a master's degree in physics from the same university.
He has published many books on philosophy and religion, and is a member of the Academy of Persian Language and Literature and the High Council of Cultural Revolution. In the early 90s Haddad-Adel also served as the vice minister of education.
Ghalibaf, Velayati and Haddad-Adel have formed a three-man pact they call the "2+1 coalition;" whereby two of them will eventually leave the race and join the other in support of his presidency.