Sudanese protest leaders were to hold talks late on Saturday with an Ethiopian envoy who has been mediating with the ruling generals and drafted a compromise blueprint for a political transition.
"The document is undergoing discussions among members of the alliance who will be meeting with Ethiopian mediator Mahmoud Dardir on Saturday to reflect their view on the proposal," the Alliance for Freedom and Change said.
Ethiopia has stepped up its efforts to resolve the political crisis in Sudan since the deadly June 3 dispersal of a long-running protest camp outside army headquarters.
At least 128 people have been killed in the crackdown, doctors linked to the protest movement say.
The health ministry put the June 3 death toll at 61 nationwide.
The raid came after the collapse of previous talks between protest leaders and the generals which hit deadlock over the composition and leadership of a new ruling body to replace the military council.
The protesters' alliance has insisted on a civilian-led transition.
The generals deny they ordered the army HQ protest broken up, insisting they authorised only a limited operation to clear drug dealers from around the camp.
It expressed "regret" over the "excesses" that happened.
On Thursday, the deputy chief of Sudan's ruling military council said the military has identified the perpetrators of the violent dispersal of a pro-democracy sit-in earlier this month, but said he won't reveal their identities because of an ongoing investigation.
On Thursday, Gen Mohamed Hamdan Dagalo, better known by his nickname Hamedti, said he won't reveal the identities of the "perpetrators" so as not to influence the probe.
Dagalo warned of impostors posing as troops among the Rapid Support Forces, who protesters blame for the bulk of the killings. Dagalo, who leads the RSF, said the military had arrested dozens of people wearing RSF uniforms and committing violations. On Wednesday alone, nine impostors were arrested, he said.
"Anyone who had crossed his limits whether they are from the military or civilians, I swear to God, will stand trial," said Dagalo in an address to a military-backed women's rally in Khartoum. He did not release any other details from the military investigation.
The military council took over the country after massive protests drove longtime president Omar Al Bashir from power in April. Negotiations with protesters reached a deadlock following the clampdown on their sit-in.
The regional Inter-Governmental Authority on Development, or Igad, said on Wednesday it was concerned about the interference of "external actors and proliferation of initiatives" to bridge the gap between the military council and protest leaders in Sudan. The group didn't name specific countries or entities it believed to be interfering in Sudanese affairs.
The main initiative to break the impasse in Sudan has been led by Ethiopia's Prime Minister Abiy Ahmed, who is also chairman of the Igad summit.
IGAD called for "all external actors to rally behind the Igad and (African Union) mediation process."
