Former Prime Minister Essam Sharaf said Saturday that boycotting the run-off presidential election or invalidating one's vote "will strengthen counter-revolutionary voting."
Sharaf said on Facebook: "No one will protect the revolution except the people who did it. All politicians have to understand the broader situation and act according to the national revolutionary reference."
"We are in the middle of an essential battle to complete the revolution. The choice now is not [to back] a [political] movement or fail it, it is either to continue or end the revolution. We have to unify and realize the gravity of the situation," he added.
Sharaf said that during the last period there were many problems that divided Egypt, including some deliberate crises engineered to bring about the current political situation.
After the first round of the presidential elections on Wednesday and Thursday, the run-off is due to be held next month between Muslim Brotherhood candidate Mohamed Morsi and Mubarak-era Prime Minister Ahmed Shafiq.
Sharaf was prime minister from March to December last year. He was initially welcomed by Tahrir Square protesters who had been demanding the resignation of Shafiq, the last prime minister appointed by toppled President Hosni Mubarak, but his cabinet was criticized for not having enough power and accused of being controlled by the ruling military leaders.
