The video shows a man, named as journalist John Cantlie, sitting at a desk, looking calm and reading from a prepared script, promising to tell the “truth” about the self-proclaimed Islamic State (IS) movement.
The video is the latest footage showing a British hostage to emerge from IS militants, following the beheading of father-of-two David Haines and the threat to kill aid worker Alan Henning.
In the latest video, Mr Cantlie, wearing orange clothing, says he is a prisoner. He asks why he has been abandoned by the United States and British governments.
IS militants are absent from the video, entitled Lend Me Your Ears and addressed to the western public.
In the video, the prisoner says: “Now, I know what you are thinking, you are thinking, ‘He is only doing this because he is a prisoner, he’s got a gun at his head and he is being forced to do this’, right?
“Well, it’s true, I am a prisoner. But, seeing as I have been abandoned by my government and my fate now lies in the hands of the Islamic State, I have nothing to lose.”
He promises that “over the next few programmes” he will show the “truth as the western media tries to drag the public back to the abyss of another war with the Islamic State”.
He adds that previous IS videos were directed at US and UK leaders, but this one was meant for the British public, particularly Muslims.
Mr Cantlie said other European governments had negotiated for the release of their hostages but the US and UK had not.
Reacting to the video, Deputy Prime Minister Nick Clegg said IS was a “murderous, medieval, terrorist outfit”.
“We didn’t need any reminding that what we’re dealing with here is a movement of almost unprecedented barbarity and cynicism,” he said.
The video featuring Mr Cantlie has been released nearly a week after footage depicting the death of Mr Haines, who grew up in Perth, the first British hostage to be killed.
It was in that video that the life of Mr Henning, 47, from Salford, was threatened. A volunteer on an aid convoy, he was seized just after crossing into Syria in December 2013.
The video of Mr Haines’ death followed the killings of US journalists James Foley and Steven Sotloff – which were also shown in videos – in August and earlier this month respectively.
Mr Cantlie, an experienced journalist, has previously been held captive in Syria – having been kidnapped in July 2012 before he escaped. He returned to Syria and it was during this trip that his second kidnap took place.
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