Updated

The little-known alternative candidate to Egypt's president in next week's election is insisting his campaign is serious, despite charges he entered the race at the last minute only to give it a veneer of legitimacy.

On the sidelines of a news conference in Cairo on Wednesday in which he described his candidacy as a patriotic duty, Moussa Mustapha Moussa says a lack of funding and donations have held his campaign back compared to President Abdel-Fattah el-Sissi's.

Moussa says he doesn't "have enough capabilities and supporters to give us free advertising, whereas president el-Sissi has that luxury" in the form of massive banners that dominate public thoroughfares in Egypt.

Critics say the March 26-28 vote is a virtual one-man referendum, after all serious competitors were arrested or intimidated into withdrawing.