Former presidential candidate Hamdeen Sabahi criticised the issuing of death penalties on Monday, a day after six Egyptian men were executed on terorrism-related charges.
“Execution is not the solution,” the leftist politician wrote on Twitter.
The six men, including one 19-year-old, were sentenced to death by a military tribunal in October on charges of plotting and carrying out deadly attacks in Qalioubiya and Cairo.
Sabahi was the only contender to challenge former army chief Abdel-Fattah El-Sisi in last year's presidential elections, garnering just 3 percent of the vote.
The Nasserist politician had come third in the first round of the presidential elections of 2012, which were won by Mohamed Morsi
A decision by a Cairo court on Saturday to seek the death sentence for ousted president Morsi and over a hundred others on charges related to a prison break in 2011 brought a barrage of criticism from foreign states, as well as local and international rights groups.