Media playback is unsupported on your device Media caption Imam Haitham al-Haddad: "Executing this man is not the answer"

Two high-profile imams in the UK have made a direct appeal to Islamic State to free British hostage Alan Henning.

In a YouTube video, Shakeel Begg and Haitham al-Haddad said there was no justification for holding the 47-year-old, who was captured in Syria.

Mr Henning, a taxi driver from Eccles in Salford, was delivering aid when he was seized last December.

Holding him captive is "totally haram [forbidden]" under Islamic law, the clerics said.

The clerics say the video is aimed at IS militants in Iraq and Syria and its supporters in the UK.

'Man of peace'

The video makes no mention of John Cantlie, a second British man being detained by IS.

Image caption Alan Henning spoke of the suffering of the Syrian people before being captured in the country

In the appeal, Mr Begg, imam at Lewisham Islamic Centre in south London, said he had campaigned for the release of Muslims from Belmarsh and Guantanamo Bay prisons.

"For the same reasons today I stand with Alan Henning," he said.

"I urge you to understand the nature of this prisoner you are holding - a man of peace."

Mr al-Haddad, an imam from the Islamic Sharia Council, describes Mr Henning as an "innocent, humanitarian aid worker".

"Executing this man is totally haram," he said. "Impermissible, prohibited according to sharia for a number of reasons.

It is not permissible whatsoever to harm a person who believes that he is safe among the people he is working with Ustadh Abu Eesa , Muslim cleric

The imam appealed directly to IS fighters to "adhere to the sharia ruling on this matter".

Both Mr Begg and Mr al-Haddad are controversial figures who have made headlines for promoting a highly conservative strand of Islam, says BBC home affairs correspondent Dominic Casciani.

A third Muslim cleric who appeared in the video appeal, Ustadh Abu Eesa - founder of the Prophetic Guidance institute in Manchester - said he personally vouched for Mr Henning.

"It is not permissible whatsoever to harm a person who believes that he is safe among the people he is working with.

"This safety must be honoured."

Image copyright Getty Images Image caption Islamic State made rapid advances through Syria and northern Iraq over the summer

He went on to warn IS that it risked "defacing" Islam by committing "the most grievous of crimes that can be committed among humans - the taking of innocent life".

Earlier this week more than 100 British Muslim imams, organisations and individuals expressed their "horror and revulsion" at the "senseless murder" of another aid worker from the UK, David Haines, and the threats to Mr Henning.

A video showing the killing of Mr Haines was recently released by IS.

His death followed that of two US hostages which were also shown in videos.

Video footage of Mr Henning - filmed before he was captured in Syria - has shown him describing his trips to the country.