Many Jabhat fighters had been recruited from other, rival militias with the promise of better-funded and better-organised units rather than for ideological reasons.

But they are said to have become disillusioned since their Syrian leader, Abu Mohammed al-Jolani, affirmed his loyalty to al-Qaeda after an apparent takeover at the top of Jabhat by hardline jihadists from Iraq.

“The group has split,” Mohammed Najib Bannan, the head of the Aleppo Judicial Committee’s military arm, said. The committee is backed by the major rebel brigades and runs civil and criminal courts in Aleppo alongside the city’s Sharia court.

Jabhat al-Nusra is also said to have withdrawn from the court system. Mr Bannan said this appeared to be the case, although Jabhat al-Nusra had made no statement on the subject. “Some of Jabhat al-Nusra supported al-Jolani’s statement, and some disagreed,” he said.