Beirut, Asharq Al-Awsat—Members of the main Western-backed Syrian National Coalition has called on all opposition factions to sign a Revolutionary Honor Code, after the Al-Qaeda-affiliated Al-Nusra Front categorically rejected it earlier this week.

The honor code has been signed by a number of what are considered to be “moderate” Islamist factions, including the Islamic Front—viewed as one of the largest and strongest opposition factions on the ground. The Islamic Front is a merger of seven Islamist groups but does not include the Al-Qaeda-inspired Islamic State of Iraq and Syria (ISIS) or the Al-Nusra Front.

But the Islamic Front has joined forces with the Al-Nusra Front in a deadly battle with ISIS over rebel-held territory in eastern Syria while simultaneously confronting Assad regime forces elsewhere.

Despite fighting on the same side against ISIS, the Al-Nusra Front has rejected the revolutionary honor code drafted by the Islamic Front.

The rebel “honor code” has nine main points, including explicitly rejecting the role of foreign jihadists in the fight to topple the regime of President Bashar Al-Assad and stressing that “jihad” should be limited to toppling the Damascus government.

The Al-Nusra Front, the official Al-Qaeda franchise in Syria, categorically rejected a number of articles in the honor code, specifically the commitment to ensuring Assad regime figures are granted a fair trial in the post-revolutionary phase.

In a statement issued on Monday, the Al-Nusra Front said: “This is contrary to Islamic Shari’a law. Apostates deserve only the sword,” adding that “the failure to seek vengeance for the people of [Syria] is nothing other than a disappointment.”

“Everyone should be aware that the Islamic state we desire is one based on religion, belief and Islamic Shari’a, before anything else. For us, Muslims cannot be equal to infidels,” the statement said. The Al-Qaeda-affiliated group also called for more “consultations” with its moderate Islamist allies.

The Western-backed Syrian National Coalition, whose military wing, the Free Syrian Army (FSA), has conducted joint operations with some of the more “moderate” Islamist rebels, has not officially commented on the Islamist-backed honor code. But senior Coalition member Fayez Sara informed Asharq Al-Awsat that the charter’s articles confirm “reveal support for the objectives of the Syrian revolution as put forward by the Syrian National Coalition.”

“I welcome the Islamist factions moving towards a new vision,” Sara said, adding that the charter “highlights the changes in the principles of the Islamic Front, from initially supporting the idea of an Islamic state to supporting the principles of the Syrian revolution, which are based on establishing a civil state.”

Another member of the Coalition, Abdul Rahman Al-Haj, told Asharq Al-Awsat: “The charter carried a message of reassurance to the West aimed at encouraging them to speed up the delivery of military support to the moderate Syrian opposition.”

Haj, an expert on Islamist groups, said: “The Al-Nusra Front had advance knowledge of the charter, because they are allies [of the Islamic Front] and are fighting battles alongside each other,” adding that ultimately the Al-Qaeda-affiliated group “could not agree to the charter’s text and its content” despite this alliance.

He called for the Al-Nusra Front, viewed by many as being less militant than ISIS—even the Al-Qaeda organization has formally distancing itself from the latter’s practices—to sign the charter. He said all of Syria’s opposition groups should band together under the banner of this honor code, saying: “We must launch joint organized military action under the same flag and ensure that unity is not only political.”

“Joint opposition strategic military operation is the only way to overthrow the regime,” the Coalition member told Asharq Al-Awsat.