DOHA - The Syrian National Council, once regarded as the leading representative of the opposition but now derided in Washington as dominated by out-of-touch exiles, was due to give its delayed response on Saturday to proposals for a new broader-based body.
The SNC had asked for two postponements while it elected its own new leadership amid strong resistance among some of its members to what they see as its sidelining in the new US-backed structure.
The group chose a Christian as its new leader in a move seen as a response to criticism that Islamists played too dominant a role, but a major activist network inside Syria, the Local Coordination Committees, announced it was quitting the bloc in protest at its position on the unity talks.
Ahead of Saturday's meeting, the SNC was expected to set out a counterproposal to the plan already agreed by most other opposition groups.
The SNC proposal envisages the formation of a provisional government pending a general congress of the opposition, according to a document.
The existing plan, inspired by leading dissident Riad Seif who is reportedly seen by Washington as a potential new opposition leader, envisages the formation of a transitional government, a military council to oversee rebel groups on the ground and a judiciary to operate in rebel-held areas.
The 10-member transitional government would be elected by a new 60-member umbrella group drawn from civilian activists and rebel fighters inside Syria as well as the exiles who have dominated the SNC.
The SNC's repeated postponement of its response to the plan drew strong criticism from other opposition groups taking part in the unity talks.
Other factions went ahead with a planned meeting without the SNC on Friday evening in frustration at a second request for a postponement.
"The SNC's requests for delays are a bad thing -- they want to take over everything and the only thing that matters to them is who forms the leadership while our number one concern ought to be the bloodshed," one dissident, Haytham Maleh, said.
Activist group the Local Coordination Committees announced on Friday that it was withdrawing from the SNC in protest at its failure adopt "serious and effective" reforms.
The SNC elected George Sabra, a Christian former communist, as its new leader with Faruk Tayfur of the Muslim Brotherhood as his deputy.
Sabra, in his first statement as SNC chief, vowed to "work with other components of the Syrian opposition to accelerate the fall of the criminal regime."