Hamdeen Sabbahi does not represent the National Salvation Front, said front secretary Omar el-Gendy on Tuesday.
Gendy told Youm 7 the front had postponed any endorsement of a presidential candidate until after the deadline to declare candidacy.
Sabbahi, a former presidential candidate, announced a few days ago his intent to run. Although he has not yet declared a candidacy, many expect Defense Minister Abdel Fatah al-Sisi to run for office.
Interim President Adly Mansour announced in late January that presidential elections would precede parliamentary elections, although dates for both have not yet been set.