The Syrian Observatory for Human Rights said today that the Daesh terrorist ‘Jihadi John’ had been killed in an air strike by US forces. However, neither the Pentagon or Downing Street could confirm that he had been killed.

Prime Minister David Cameron issued a statement earlier saying that his Government had been working closely with the Americans to target Islamic State in Syria, but failed to state that the man who had beheaded several Westerners had actually been killed. Later, speaking outside Downing Street, David Cameron said it was too early to be sure that the strike had succeeded in killing the terrorist.

However, he defended the action, saying it was nothing more than an act of 'self-defence'.

The target, whose real name is Mohammed Emwazi, was born in Kuwait but his family moved to London in 1994, when he was six. His nickname was given by those he captured, being part of a group of four British terrorists who were named after the four members of The Beatles, a fact that disgusted the remaining members of the pop band.

Between 2014 and 2015 he generated international revulsion when he appeared to behead a number of hostages, including James Foley, David Haines and Alan Henning.

This led to an international manhunt involving the FBI, MI5 and Scotland Yard, but apart from his accent, there was little to identify him from the videos in which he appeared.

Other images later appeared that helped to identify him, but the peripatetic nature of the Islamic State made it harder to identify where he, or any of the IS leaders, were actually located.

The latest news that an American strike force had targeted him will raise the stakes in the UK Parliament about extending British involvement in Syria.

Currently, the mandate extends only to Iraq and although David Cameron is in favour of extending that action to Syria, the base of the Islamic State, there has been reluctance to call a vote after a failed attempt in 2013.

Labour Party leader Jeremy Corbyn is known to be opposed to further involvement, although Defence Secretary Michael Fallon has said that it is ‘morally indefensible’ not to target IS in Syria.

The Parliamentary numbers make it even more difficultas the SNP MPs are thought to be opposed to extending British military action as well.

The politics have become even more complicated since Russia entered the equation in support of the regime of Bashar al-Assad. Western commentators have complained that their air strikes are targeting opponents of the Syrian leader rather than the Islamic State. However, that is not seen as a barrier to UK involvement there, and would be seen to be augmenting the allied forces targeting IS.

However, the latest development will increase pressure on the Labour leader because of his pacifist stance. One right-wing MP questioned why ‘are we leaving it to the Americans’. But whether this latest development will swing opposition MPs is a calculation that the Government will have to take when the House of Commons gets back to business next week.