Originally published: 07.00

The British Prime Minister David Cameron has vowed to hunt down the 'barbaric and repulsive terrorists' responsible for beheading British aid worker Alan Henning. Cameron called the killing by Islamic State militants is "abhorrent" and "unforgiveable". 

Islamic State militants posted a video of the murder online last night.

There is now speculation over whether the UK should extend airstrikes into Syria.

Sky's Chief Political correspondent Joey Jones is in Downing Street.