“Idriss has done well as an interlocutor with the West and the Gulf, but the military situation is degenerating … It is not too late to save it but he does not have much time,” said a senior opposition figure who did not want to be named.

“The Islamists do not like Idriss but they do not hate him either,” the source said.

Islam Alloush of the Liwa al-Islam brigade, one of the strongest Islamist rebel units, said his group is willing to cooperate with Idriss and is in touch with the Military Council.

“We consider any one who is fighting to rid Syria of Bashar al-Assad to be with us,” Alloush said.

Strengthening the Military Council with arms would help the moderates carve a bigger role in the military struggle against Assad and redress the balance of power with Islamist rebel units, especially in eastern Syria, where Salafist groups such as Ahrar al-Sham and al-Qaeda linked Nusra Front almost singlehandedly captured the city or Raqqa.