Presidential hopefuls Hamdeen Sabbahi, Abdel-Moneim Abul-Fotouh and Amr Moussa did not attend Saturday's meeting called by the Muslim Brotherhood and the Freedom and Justice Party (FJP) to co-ordinate support for Mohamed Mursi in June's presidential runoff, according to Yehia Hamed, a FJP spokesman.
The reasons for their non-attendance have not been revealed.
However, a member of Sabbahi's campaign told Ahram Online on Friday that the Nasserist candidate would not attend but would announce his position at a separate press conference on Saturday at 8pm.
Representatives from other political groups were in attendance, including Essam Sultan MP of the moderate Islamist Wasat Party, Salah Abdel-Maqsoud and Mahdi Akef of the Brotherhood, Ghad Al-Thawra Party leader Ayman Nour and presidential also-ran Abdullah El-Ashaal.
Safwat Abdel-Ghani of Al-Gamaa Al-Islameya, who also attended, has called for the Brotherhood's presidential candidate, Mursi, to hold a press conference and give assurances that he will be a president for all Egyptians.
Asked before the meeting if the Brotherhood would accept an Ahmed Shafiq victory in the runoff, Abdel-Maqsoud said: "We are ready to work with anyone but we can never work with someone who is accused of corruption and embezzling public money, like Ahmed Shafiq."
He added that the meeting would focus on trying to unite all revolutionary forces behind a candidate that represented the revolution, suggesting Mohamed Mursi was such a man.
Abul-Ela Madi, head of the Wasat Party, said his party wanted Mursi to form a consensus government headed by somebody who was not from the Brotherhood, saying the Brotherhood's performance during the transitional period has been a failure.
He added that Abul-Fotouh and Sabbahi would be politically rewarded if they called on their supporters to vote for Mursi in the presidential election run-off against Shafiq.
Madi did not mention if the Brotherhood had accepted their demands.
During the meeting, Ayman Nour told Ahram Online that liberals wanted a secular constitution that maintained equality between Egyptians, as well as freedom of the media.
"We do not want an instant reply [to our demands]; however, we demand a written declaration from the Brotherhood with their answer that can be announced to all Egyptians," he added.
Abul-Fotouh said via Twitter that, "We seek to build a consensus against the remnants of the former regime, answer the demands of the revolution and develop a project for the nation that fairly accommodates all Egyptians." He added that he would not be part of a deal to distribute positions.
El-Erian stressed at a press conference on Friday that cooperation between Egypt's political and socio-economic groups remained a priority for the Muslim Brotherhood and its political wing the FJP.
"We were the first to call for the Democratic Alliance [electoral coalition] during the parliamentary elections, which brought together 40 different parties," added El-Erian.