A coalition of eight Egyptian opposition parties and some 150 pro-democracy public figures are calling on voters to boycott the March presidential election, saying it amounts to a "farce" or "absurdity bordering on madness."

The incumbent, general-turned-president Abdel-Fattah el-Sissi, is virtually certain to win the March 26-28 vote, sweeping aside a face-saving would-be candidate whose last-minute participation spared the government the embarrassment of a one-candidate election.

Tuesday's call for a boycott by the Civilian Democratic Movement comes just days after five opposition figures, including a 2012 presidential candidate and two top campaign aides for now-arrested presidential hopeful Sami Annan, called for a boycott of the vote and on Egyptians not to recognize the vote's outcome if it goes ahead.