A group of prominent Syrian opposition members on Tuesday criticized the role of the Muslim Brotherhood in the Syrian National Coalition and accused regional governments of "hegemony" over the body.
In a letter addressed to the Arab League, which is meeting in Doha, the group warned that the opposition was experiencing a crisis as a result.
"The crisis in the Syrian opposition is worsening... [because of] what is happening inside the National Coalition and the actions of those who dominate it," the letter said.
It criticized "the conflicts between the leaders of the coalition, the dictatorial control exercised by one of its currents over its decisions and actions, and the flagrant hegemony of diverse Arab and regional players."
Though the letter made no explicit reference to the Brotherhood, it came amid discontent in the opposition over the election of the first rebel prime minister, Ghassan Hitto, widely understood to have been the Brotherhood choice.
And it follows accusations that countries backing the rebels, including Qatar and Saudi Arabia, have directly interfered in the decisions of the Coalition, which is the main opposition grouping.
The letter urges the "abandoning of the project of an interim government, which has caused broad national division and has been strongly opposed by the leadership and fighters of the Free Syrian Army."
The signatories, who include several liberal activists such as Michel Kilo, Abdel Razzak Eid, Walid al-Bunni and Basma Kodmani, called instead for the creation of an executive body or consensus government chosen by a broad spectrum of the opposition.
The letter also urged "restructuring the Coalition to balance it and keep it beyond the control of any one party or current."
It seeks to reserve 25 seats for secular, liberal members and calls for increased representation of women.
Hitto, elected earlier this month, has been tasked with naming a government, which would be approved by the organization.
He has pledged to name a technocratic cabinet, without regard for political affiliation.
But within the opposition there are serious disagreements over the wisdom of forming an interim government, and discomfort over the election of Hitto by ballot rather than on the basis of a consensus decision.
During last week's meeting to elect the prime minister, several members of the Coalition walked out, and others have since announced they are freezing their participation in the body.
And on Sunday, Coalition chief Ahmed Moaz al-Khatib announced he was resigning from his post.
"I announce my resignation from the National Coalition, so that I can work with a freedom that cannot possibly be had in an official institution," he said.
He had reportedly wanted to quit for some time, in part over his objections to the naming of an interim premier, but the Coalition has yet to accept his resignation.
Despite the decision, Khatib agreed to represent Syria's opposition at the Arab League summit underway in Doha, the first time rebels have taken possession of Syria's seat in the body.