Senior religious leaders in Iraq are preparing to sign an unprecedented “fatwa against violence” that will help reconcile the rival Sunni and Shia branches of Islam and herald new hopes for peace in the war-torn country.

The fatwa, negotiated by the peace organisation run by the Anglican “Vicar of Baghdad” Canon Andrew White, will mark a significant move towards a settlement between the Shia and Sunni communities and ease the process towards a political solution.

It comes in the context of plummeting fatalities among both coalition troops and civilians and is a further vindication of the“surge” security strategy of US General and Iraq commander David Petraeus.

Canon White, who will tonight be presented with the first Woolf Institute “Pursuer of Peace Award” in London in recognition of his work in the Middle East, said the fatwa was to be signed by Sheikh Ahmed al Kubaisi, acknowledged by Iraqis as the senior Sunni religious authority and whose Friday sermons from Dubai reach 20 million, and Ayatollah Sayyid Ammar Abu Ragheef, chief of staff for Grand Ayatollah Ali al

Sistani, leader of the Shia community in Iraq and beyond. The fatwa, which will have the equivalence of statutory authority for all Shia and Sunni Muslims in Iraq, is the culmination of years of dialogue with religious leaders behind the scenes in Iraq and throughout the region by Canon White. It follows a meeting in Cairo in August organised by Canon White’s Foundation for Relief and Reconciliation in the Middle East, at which the two Islamic leaders were present and where they agreed to “end terrorist violence” and to work towards the fatwa.

The meeting was described by the Wall Street Journal as “truly historic”. Robert McFarlane, a former national security adviser to Ronald Reagan, wrote in the Journal: “A fatwa such as this will carry the force of law for all followers. Think about that. After more than four years of brutal warfare and untold suffering, the leading religious authorities in Iraq have joined hands and said “Enough,” and have committed to use their authority to bring peace to their country.

Speaking to The Times in London, Canon White, who has seen six of his Baghdad church leaders killed and 45 members kidnapped and not returned since the present campaign began, said: “The fatwa will definitely happen.” He said that a military solution to Iraq on its own had no chance of working. “One of the key things is getting the governments to recognise that.” But a reconciliation solution on its own would also be ineffective.

“There is not a quick, easy solution,” he continued. “This is long-term work. We have to engage with these people continually. The key thing is talking to them every day. Never before has there been a Sunni-Shia fatwa against violence. It has never been heard of in history. Will it make a difference? Not immediately. But I hope eventually it will.”

Tonight’s award to Canon White is being made by the influential Woolf Institute of Abrahamic Faiths, based in Cambridge and dedicated to promoting understanding between Muslims, Christians and Jews. Institute director Dr Edward Kessler said the award was for “Andrew’s tireless work in bringing hope to broken people in a torn region.”

Canon White, Vicar of St George’s Church in Baghdad and International Director of the Iraqi Institute of Peace, has in recent years acted as a negotiator in many conflict and hostage situations including the siege of the Church of the Nativity in Bethlehem in 2002 and the riots between Muslims and Christians in Northern Nigeria in 2004. In July this year he briefly left Iraq after receiving death threats for attempting to secure the release of five British hostages seized in May.