Some 3000 people packed the Lawyers Syndicate on Wednesday for a gathering where often fractious opposition groups made a show of unity, with the supreme leader of the Muslim Brotherhood standing with leftist and secular activists.
"Suffering from oppression, despotism and absence of freedom is uniting us," said Brotherhood leader Muhammad Mahdi Akif.
"We are not calling for a revolution, we're calling for right and peace, to establish freedom," he said.
Akif's deputy Muhammad Habib said: "Why don't we all join forces under one banner? That will happen, God willing. We have common ground and will seek to reach an agreement."
The meeting launched the National Coalition for Democratic Transformation, headed by former prime minister Aziz Sidqi and included judges and intellectuals from different ideological backgrounds.
The Brotherhood and the reform movement Kifaya attended to show their support for the new group.
"Suffering from oppression, despotism and absence of freedom is uniting us"
Muhammad Mahdi Akif,
"We are a republic and we won't accept succession," Sidqi said. "The silent majority, whom we are addressing, have to choose who rule them."
Police cars lined the road to the Syndicate where the group held its first meeting. At least 2000 people filled a conference hall and spilled into the outside garden where two huge screens were erected.
Even passersby watched from the street as opposition figures barely on talking terms before sat next to each other at the podium.
The formation of the National Coalition for Democratic Transformation was announced last month.
The Muslim Brotherhood, Egypt's largest Islamic group, has been banned since 1954 and long refrained from provoking the government, but has engaged in protests since March demanding political reform.
The mainstream Egyptian movement for change known as Kifaya was the first to come out against President Hosni Mubarak and the possibility that his son Gamal would succeed him.
Many have taken to the streets
in recent months in protests
Mubarak, 77, has been in power since 1981.
Voting in upcoming elections "would give new legitimacy for a defunct regime", said George Ishak, a leading member of Kifaya.
Instead, he called for all forces to join hands to sue the government over a "forged referendum" - the May national vote for a constitutional amendment which was passed to pave the way for multi-party candidates.
One woman held a banner that said: "We've finally learned to say 'No' even if they shoot us."