UK missile strike to kill British jihadi in Syria a 'significant' step

The announcement that a British missile killed Reyaad Khan and another UK citizen two weeks ago is significant.

The British military is not authorised to carry out air strikes in Syria - unlike in neighbouring Iraq.

Two years ago, Parliament refused to authorise it.

But government sources say this strike was justified as British intelligence services had established Mr Khan was planning a direct terror threat on UK soil.

Authorisation was sought - and received - from the government's chief legal officer, the Attorney General.

A Whitehall aide tells me 'a window of opportunity' became available on 21 August and the strike was given the green light by the Defence Secretary.

Reyaad Khan - who left his home Cardiff to fight with ISIS in Syria - was killed along with another as yet unnamed Briton who has been described to me as 'an ISIS associate'.

British aircraft are authorised to carry out airstrikes against ISIS targets in Iraq but over Syria the UK military can only carry out surveillance operations.

David Cameron wants MPs to authorise airstrikes in Syria - as ISIS operates across the border.

But he was expected to wait for the Labour leadership result before doing so.