Russia has up to 200 intelligence officers in Britain, more than five times as many as during the Cold War, and at least 500 agents who provide information, according to a report to be published within weeks.

The Henry Jackson Society think tank interviewed serving and recent former intelligence officials to produce the figure, which is significantly higher than previous estimates. It will add to growing alarm about Russian espionage activities in Britain following the attempted murder of Sergei and Yulia Skripal in March.

Even after the expulsions of 23 suspected intelligence officers after the Skripal attack, about half of the 56 accredited Russian diplomats still in London are believed to be engaged in intelligence work, the report says. Others operate without diplomatic cover. Several