Britain's intelligence services can "degrade" the Kremlin’s cyber capabilities in the same way they dismantled Isil’s online propaganda machine, the director of GCHQ has said.

Jeremy Fleming said that the surveillance agency’s expertise has never been in greater demand in the wake of the Salisbury attack, as he accused the Kremlin of “blurring the boundaries” between state and criminal activity.

Speaking at a cyber security conference in Manchester yesterday, the former MI5 officer likened Russia’s growing list of “reckless” transgressions to the Islamist terror group, adding that the agency stood ready to deal with both state and non-state actors.

In the same way that GCHQ helped “systemically and persistently” thwart Isil’s online network, Mr Fleming said the agency was testing its cyber defences against Russia in a manner similar to the emergency services preparing for a crisis.