British Muslims have led condemnation of the murder of British hostage Alan Henning, labelling it a “despicable and offensive act” that showed the Islamic State jihadists who killed him had “no regard for Islam”.

Imams and other influential figures had joined forces to appeal to the terrorists to release the aid worker, a former taxi driver from Manchester in northwest England who left his job to take aid to victims of Syria’s civil war.

Shuja Shafi, secretary general of the Muslim Council of Britain, said: “This reported murder is a despicable and offensive act, coming as it does on the eve of the Muslim festival of Eid Al-Adha.

“It is quite clear that the murderers of Alan Henning have no regard for Islam, or for the Muslims around the world who pleaded for his life.

“Alan was a friend of Muslims, and he will be mourned by Muslims.

“In this period of Hajj and this festival of Eid, Muslims remember the mercy of God and the emphasis God places on human life.

“Alan Henning’s murderers have clearly gone against that spirit of Islam. Our thoughts and prayers go out to his family.”

Respect Party MP George Galloway described the killing as “a depraved Satanic act committed by devils in human form”.

He wrote on Twitter: “It is a desecration of all that is holy.”

Conservative MP Mark Pritchard said: “If ISIS (another term for IS) think the British people will be cowed, they are gravely mistaken. For every act of brutality they birth greater national resilience.”

And Labour’s Fiona Mactaggart, who did not vote in last week’s decision by the British parliament to join US-led air strikes against IS positions in Iraq, said the murder made her question herself.

“The vile murderers of ISIL (another term for IS) make me almost wish I voted to bomb in Iraq last week,” she said. “I want to avenge the death of Alan Henning. I despise them.”