David Cameron has branded Islamic State terrorists who killed British aid worker Alan Henning 'brutal and repulsive' as the Prime Minister led a wave of global revulsion over the murder. He vowed to 'hunt down' and bring to justice the man who wielded the knife, who has become known as Jihadi John - as Barack Obama, Nick Clegg and Muslim leaders all spoke of their disgust. Mr Henning, 47, a father-of-two, was filmed being murdered in a video posted on the internet three weeks after he was last paraded in front of a camera. Scroll down for video . David Cameron has branded the Islamic State 'brutal and repulsive' tonight after British aid worker Alan Henning was filmed being beheaded by the terrorist dubbed Jihadi John . In a strongly-worded statement, Mr Cameron said: 'We will do all we can to hunt down these murderers and bring them to justice.' He added: 'My thoughts and prayers tonight are with Alan’s wife Barbara, their children and all those who loved him. ‘Alan had gone to Syria to help get aid to people of all faiths in their hour of need. 'The fact that he was taken hostage when trying to help others and now murdered demonstrates that there are no limits to the depravity of these ISIL terrorists. David Cameron received a security briefing this morning before calling the slaying of Alan Henning 'completely unforgivable' Aid worker Alan Henning, 44, a father-of-two, was kidnapped by Islamist rebels on Boxing Day last year . This morning, Downing Street revealed that Mr Cameron was meeting with officials from the intelligence agencies, the military and the Foreign Office at his official country residence Chequers to discuss the killing. Later this morning, he called the slaying 'completely unforgivable' adding that there was 'no level of depravity to which they will not sink'. 'No appeals made any difference,"Mr Cameron told Sky News. 'The murder of Alan Henning is absolutely abhorrent, it is senseless, it is completely unforgivable. Anyone in any doubt about this organisation can now see how truly repulsive it is, and barbaric it is,' he said of IS. When asked whether he believed the extremists would kill more of their Western hostages, Cameron suggested the only way to stop them was through military action. 'The fact that this was a kind, gentle, compassionate and caring man who had simply gone to help others, the fact they could murder him in the way they did, shows what we are dealing with,' he said. Nick Clegg took to Twitter to praise Mr Henning, saying he worked to 'selflessly help those in need' 'This is going to be our struggle now. ... We must do everything we can to defeat this organisation. We must take action against it. We must find those responsible.' Deputy Prime Minister Nick Clegg praised Mr Henning on Twitter, saying: 'Sincere condolences to Alan Henning's family. Barbaric actions of ISIL are held in complete contempt. 'We are resolved to defeat this evil. Alan Henning was a man moved to selflessly help those most in need and we should remember that above all else at this difficult time.' Labour leader Ed Miliband said: 'The murder of Alan Henning by ISIL is appalling and barbaric. 'He was an aid worker, helping those in need. Those who killed him have revealed only their lack of humanity and brutality. 'My thoughts and deepest condolences are with his wife Barbara, his children and all those who knew him. 'We will do everything we can to support the efforts of the Government to bring those guilty of this terrible act to justice.' U.S. President Barack Obama said: 'The United States strongly condemns the brutal murder of United Kingdom citizen Alan Henning by the terrorist group ISIL. 'Mr Henning worked to help improve the lives of the Syrian people and his death is a great loss for them, for his family, and for the people of the United Kingdom. 'Standing together with our UK friends and allies, we will work to bring the perpetrators of Alan's murder - as well as the murders of Jim Foley, Steven Sotloff and David Haines - to justice. 'Standing together with a broad coalition of allies and parteners, we will continue taking decisive action to degrade and ultimately destroy ISIL.' The American ambassador to the UK Matthew Barzun said this morning: 'Today, we stand with the UK in joint determination, resolve and commitment to achieve justice for Alan Henning.' Imams  had joined forces before Mr Henning's execution to appeal to the terrorists to release the former taxi driver from Salford, who left his job to travel to Syria to take help to victims of its civil war. Mohammed Shafiq, chief executive of the Ramadhan Foundation, a Muslim charity, called Henning 'a British hero.' His 'barbaric killing is an attack against all decent people around the world,' Shafiq said. Dr 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. Barack Obama condemned the killing, and reiterated his promise to 'degrade and ultimately destroy' ISIS . '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.' Hanif Qadir, founder of Active Change Foundation – the organisation behind the #Notinmyname campaign said: 'The fact that they have chosen to commit this barbaric act on the eve of the Eid al-adha, a global expression of forgiveness and mercy among Muslims, only demonstrates the extent of the evil and barbaric nature of these criminals. 'They have not shown any ounce of mercy or compassion and are therefore totally against Islam and are hell-bent on killing innocent individuals and must be stopped. 'As a British Muslim I urge every other Muslim in the UK to stand up and refute these terrorists and distance themselves from this brutality and false Islam.' In footage released on social media, Mr Henning is shown being beheaded by Jihadi John, the Islamist fighter who was also behind the killings of U.S. journalists James Foley and Steven Sotloff, and British aid worker David Haines. Former Foreign Office minister Baroness Warsi, the first Muslim woman in the Cabinet, tweeted her condolences, saying the Mr Hennning was the 'true martyr.' Liberal Democrat party president Tim Farron said: ‘Alan Henning should be remembered for what he was - a kind hearted, selfless man who wanted to help others. My prayers are with his family.’ Inspire, an anti-extremist campaign group of British Muslim women, described Mr Henning's death as 'an affront to all Muslims across the world'. Co-director Sara Khan expressed her 'heartfelt condolences' to the family of the aid worker, who she described as an 'amazing man, a man of courage, a man of dignity, a man of integrity'. She said: 'The only thing that the killing of Alan has achieved is greater revulsion for ISIS and the fact that more people from across our world, within our communities, Muslims and non-Muslims alike, are united in their stance against their barbarity and inhumanity. Mohammed Shafiq, chief executive of the Ramadhan Foundation, a Muslim charity, called Alan Henning (pictured) 'a British hero.' 'The murder of Alan Henning is a brutal and criminal act of terror that is an affront to all Muslims across the world.' Former head of the Army, General The Lord Dannatt said the deaths of hostages were sadly 'part of the harsh price' to be paid in confronting the 'abomination' of IS. 'Our Government is now standing up to its responsibilities and part of the harsh price, while this takes time, is that sadly if they have hostages in their hands, these atrocious things seem to be happening and seem to be going to continue to happen,' he told BBC Radio 4's Today. He renewed his call for the UK to extend military operations to Syria, where the US and other allies are conducting air strikes, saying this country was 'practically not doing enough'. 'Dealing with half a problem is not going to solve the problem,' he said. 'If the Americans have found a way to be able to do this then actually we should be doing it.' This morning, Mr Cameron met with officials from the intelligence agencies, the military and the Foreign Office at his official country residence Chequers to discuss the killing. Afterwards, a Downing Street statement said the Prime Minister had raised a second video showing a British ISIL fighter unmasked delivering a further message - and that police were investigating 'urgently' for 'possible terrorism offences' relating to it. A second video, published by Islamic State last night, shows an injured British fighter challenging David Cameron to send ground troops to Iraq. The fighter is believed to be a former Morrisons security guard who flew to Syria . It comes after footage emerged last night of an injured British fighter challenging David Cameron to send ground troops to Iraq. In a rant directed at ‘that despicable swine David Cameron’, the unmasked jihadi said: ‘Send them all, send your reserves and your backup and we’ll send them back one by one in coffins.’ It is understood the jihadist in the video is former supermarket security guard Omar Hussain. The 27-year-old from High Wycombe previously worked for Morrisons as a security guard. He lived with his mother and brothers before travelling to Syria in January 2014. The Downing Street statement said: 'The PM was clear that we must keep doing all we can to ensure that these terrorists are found and brought to justice for their heinous crimes and we will keep working with our US partners and those in the region to do this. 'ISIL’s brutality will not persuade us to change our approach. 'Indeed, the senseless murder of an innocent man only reinforces our resolve to defeat this terrorist organisation and to eradicate the threat they pose to Britons - whether those in the region or here on the streets of the UK. 'At the meeting, the Prime Minister also raised a second video released last night which shows an apparent British ISIL fighter unmasked delivering a further message. 'The police are urgently investigating the contents of the video, including possible terrorism offences relating to it.'
David Cameron vows to hunt down terrorists behind Mr Henning's killing .
Nick Clegg and Ed Miliband also condemn video posted on social media .
Muslim leaders dub Henning a 'British hero' and say murder is against Islam .
Alan Henning, a father-of-two, has been beheaded in terror group video .
PM meeting with officials from the intelligence agencies to discuss the killing .
U.S. President Barack Obama this morning condemned the 'brutal murder'
Police 'urgently' investigate second video showing unmasked British ISIL fighter .
David Cameron has branded Islamic State terrorists who killed British aid worker Alan Henning 'brutal and repulsive' as the Prime Minister led a wave of global revulsion over the murder. He vowed to 'hunt down' and bring to justice the man who wielded the knife, who has become known as Jihadi John - as Barack Obama, Nick Clegg and Muslim leaders all spoke of their disgust. Mr Henning, 47, a father-of-two, was filmed being murdered in a video posted on the internet three weeks after he was last paraded in front of a camera. Scroll down for video . David Cameron has branded the Islamic State 'brutal and repulsive' tonight after British aid worker Alan Henning was filmed being beheaded by the terrorist dubbed Jihadi John . In a strongly-worded statement, Mr Cameron said: 'We will do all we can to hunt down these murderers and bring them to justice.' He added: 'My thoughts and prayers tonight are with Alan’s wife Barbara, their children and all those who loved him. ‘Alan had gone to Syria to help get aid to people of all faiths in their hour of need. 'The fact that he was taken hostage when trying to help others and now murdered demonstrates that there are no limits to the depravity of these ISIL terrorists. David Cameron received a security briefing this morning before calling the slaying of Alan Henning 'completely unforgivable' Aid worker Alan Henning, 44, a father-of-two, was kidnapped by Islamist rebels on Boxing Day last year . This morning, Downing Street revealed that Mr Cameron was meeting with officials from the intelligence agencies, the military and the Foreign Office at his official country residence Chequers to discuss the killing. Later this morning, he called the slaying 'completely unforgivable' adding that there was 'no level of depravity to which they will not sink'. 'No appeals made any difference,"Mr Cameron told Sky News. 'The murder of Alan Henning is absolutely abhorrent, it is senseless, it is completely unforgivable. Anyone in any doubt about this organisation can now see how truly repulsive it is, and barbaric it is,' he said of IS. When asked whether he believed the extremists would kill more of their Western hostages, Cameron suggested the only way to stop them was through military action. 'The fact that this was a kind, gentle, compassionate and caring man who had simply gone to help others, the fact they could murder him in the way they did, shows what we are dealing with,' he said. Nick Clegg took to Twitter to praise Mr Henning, saying he worked to 'selflessly help those in need' 'This is going to be our struggle now. ... We must do everything we can to defeat this organisation. We must take action against it. We must find those responsible.' Deputy Prime Minister Nick Clegg praised Mr Henning on Twitter, saying: 'Sincere condolences to Alan Henning's family. Barbaric actions of ISIL are held in complete contempt. 'We are resolved to defeat this evil. Alan Henning was a man moved to selflessly help those most in need and we should remember that above all else at this difficult time.' Labour leader Ed Miliband said: 'The murder of Alan Henning by ISIL is appalling and barbaric. 'He was an aid worker, helping those in need. Those who killed him have revealed only their lack of humanity and brutality. 'My thoughts and deepest condolences are with his wife Barbara, his children and all those who knew him. 'We will do everything we can to support the efforts of the Government to bring those guilty of this terrible act to justice.' U.S. President Barack Obama said: 'The United States strongly condemns the brutal murder of United Kingdom citizen Alan Henning by the terrorist group ISIL. 'Mr Henning worked to help improve the lives of the Syrian people and his death is a great loss for them, for his family, and for the people of the United Kingdom. 'Standing together with our UK friends and allies, we will work to bring the perpetrators of Alan's murder - as well as the murders of Jim Foley, Steven Sotloff and David Haines - to justice. 'Standing together with a broad coalition of allies and parteners, we will continue taking decisive action to degrade and ultimately destroy ISIL.' The American ambassador to the UK Matthew Barzun said this morning: 'Today, we stand with the UK in joint determination, resolve and commitment to achieve justice for Alan Henning.' Imams  had joined forces before Mr Henning's execution to appeal to the terrorists to release the former taxi driver from Salford, who left his job to travel to Syria to take help to victims of its civil war. Mohammed Shafiq, chief executive of the Ramadhan Foundation, a Muslim charity, called Henning 'a British hero.' His 'barbaric killing is an attack against all decent people around the world,' Shafiq said. Dr 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. Barack Obama condemned the killing, and reiterated his promise to 'degrade and ultimately destroy' ISIS . '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.' Hanif Qadir, founder of Active Change Foundation – the organisation behind the #Notinmyname campaign said: 'The fact that they have chosen to commit this barbaric act on the eve of the Eid al-adha, a global expression of forgiveness and mercy among Muslims, only demonstrates the extent of the evil and barbaric nature of these criminals. 'They have not shown any ounce of mercy or compassion and are therefore totally against Islam and are hell-bent on killing innocent individuals and must be stopped. 'As a British Muslim I urge every other Muslim in the UK to stand up and refute these terrorists and distance themselves from this brutality and false Islam.' In footage released on social media, Mr Henning is shown being beheaded by Jihadi John, the Islamist fighter who was also behind the killings of U.S. journalists James Foley and Steven Sotloff, and British aid worker David Haines. Former Foreign Office minister Baroness Warsi, the first Muslim woman in the Cabinet, tweeted her condolences, saying the Mr Hennning was the 'true martyr.' Liberal Democrat party president Tim Farron said: ‘Alan Henning should be remembered for what he was - a kind hearted, selfless man who wanted to help others. My prayers are with his family.’ Inspire, an anti-extremist campaign group of British Muslim women, described Mr Henning's death as 'an affront to all Muslims across the world'. Co-director Sara Khan expressed her 'heartfelt condolences' to the family of the aid worker, who she described as an 'amazing man, a man of courage, a man of dignity, a man of integrity'. She said: 'The only thing that the killing of Alan has achieved is greater revulsion for ISIS and the fact that more people from across our world, within our communities, Muslims and non-Muslims alike, are united in their stance against their barbarity and inhumanity. Mohammed Shafiq, chief executive of the Ramadhan Foundation, a Muslim charity, called Alan Henning (pictured) 'a British hero.' 'The murder of Alan Henning is a brutal and criminal act of terror that is an affront to all Muslims across the world.' Former head of the Army, General The Lord Dannatt said the deaths of hostages were sadly 'part of the harsh price' to be paid in confronting the 'abomination' of IS. 'Our Government is now standing up to its responsibilities and part of the harsh price, while this takes time, is that sadly if they have hostages in their hands, these atrocious things seem to be happening and seem to be going to continue to happen,' he told BBC Radio 4's Today. He renewed his call for the UK to extend military operations to Syria, where the US and other allies are conducting air strikes, saying this country was 'practically not doing enough'. 'Dealing with half a problem is not going to solve the problem,' he said. 'If the Americans have found a way to be able to do this then actually we should be doing it.' This morning, Mr Cameron met with officials from the intelligence agencies, the military and the Foreign Office at his official country residence Chequers to discuss the killing. Afterwards, a Downing Street statement said the Prime Minister had raised a second video showing a British ISIL fighter unmasked delivering a further message - and that police were investigating 'urgently' for 'possible terrorism offences' relating to it. A second video, published by Islamic State last night, shows an injured British fighter challenging David Cameron to send ground troops to Iraq. The fighter is believed to be a former Morrisons security guard who flew to Syria . It comes after footage emerged last night of an injured British fighter challenging David Cameron to send ground troops to Iraq. In a rant directed at ‘that despicable swine David Cameron’, the unmasked jihadi said: ‘Send them all, send your reserves and your backup and we’ll send them back one by one in coffins.’ It is understood the jihadist in the video is former supermarket security guard Omar Hussain. The 27-year-old from High Wycombe previously worked for Morrisons as a security guard. He lived with his mother and brothers before travelling to Syria in January 2014. The Downing Street statement said: 'The PM was clear that we must keep doing all we can to ensure that these terrorists are found and brought to justice for their heinous crimes and we will keep working with our US partners and those in the region to do this. 'ISIL’s brutality will not persuade us to change our approach. 'Indeed, the senseless murder of an innocent man only reinforces our resolve to defeat this terrorist organisation and to eradicate the threat they pose to Britons - whether those in the region or here on the streets of the UK. 'At the meeting, the Prime Minister also raised a second video released last night which shows an apparent British ISIL fighter unmasked delivering a further message. 'The police are urgently investigating the contents of the video, including possible terrorism offences relating to it.'
David Cameron has branded Islamic State terrorists Jihadi John - as Barack Obama, Nick Clegg and murdered in a video posted on the internet three officials from the intelligence agencies, the country residence Chequers to discuss the killing. Later this morning, he called the Ed Miliband said: 'The murder of Alan Henning by U.S. President Barack Obama said: 'The United States strongly condemns the brutal murder of released on social media, Mr Henning is shown British Muslim women, described Mr Henning's (pictured) 'a British hero.' 'The murder of Alan Cameron met with officials from the intelligence second video showing a British ISIL fighter