"The worst possible scenario," said Ahmed Khairy, spokesman for the Free Egyptians Party, one of the secular, liberal parties that emerged last year. Speaking to the Al-Ahram daily, he described Morsi as an "Islamic fascist" and Shafiq as a "military fascist."
He said it would be hard to endorse either in the June 16-17 runoff.
The head-to-head match between Morsi and Shafiq will likely be a heated one. Each has die-hard supporters but is also loathed by significant sectors of the population.
The first-round race, held Wednesday and Thursday, turned out close. By Friday evening, counts from stations around the country reported by the state news agency gave Morsi 25.3 percent and Shafiq 24.9 percent with less than 100,000 votes difference.
A large chunk of the vote - more than 40 percent - went to candidates who were seen as more in spirit of the revolution that toppled Mubarak, that is, that they were neither from the Brotherhood nor from the so-called feloul, or "remnants" from the old, autocratic regime. In particular, those votes went to leftist Hamdeen Sabahi, who narrowly came in third in a surprisingly strong showing of 21.5 percent, and a moderate Islamist who broke with the Brotherhood, Abdel-Moneim Abolfotoh.
The Brotherhood, which already dominates parliament and hopes the presidency can seal its rise to power, scrambled to try to draw the revolution vote to its side. It invited other candidates and revolutionary groups to meet Saturday to "save the nation and the revolution" ahead of an expected fierce race.
It likely faces a tough task. Over the last six months, the Brotherhood has disillusioned many of those figures with plays for power that left its would-be allies feeling betrayed and deepened the Brotherhood's reputation as domineering and arrogant.
"Egypt is going through a truly historic transformation," senior Brotherhood figure Essam el-Erian said. "We hope the runoff is more heated, more clear and more representative of the spirit of the January 25 revolution.
Shafiq's camp was making a similar appeal.
"We know the Muslim Brotherhood stole the revolution from the youth," said Shafiq's spokesman, Ahmed Sarhan. "Our program is about the future. The Muslim Brotherhood is about an Islamic empire. That is not what (the youth groups) called for" in the revolution.
The breakdown of the first round voting provided multiple surprises.
Shafiq's strong showing would have been inconceivable a year ago amid the public's anti-regime fervor. He was Mubarak's last prime minister and was himself forced out of office.
A former air force commander and personal friend of Mubarak, he campaigned overtly as an "anti-revolution" candidate in the presidential election, criticizing the revolutionary protesters.