Ken McCallum says Kremlin attempted to influence vote through social media and TV reports but had little impact

Russia did try to interfere in the Brexit referendum through social media and television reports, the head of MI5 said on Tuesday, but he added that did not mean the Kremlin had any impact on the result.

Ken McCallum endorsed comments by Andy Burnham, who raised the issue over the past two days, though he said continuing to debate it risked giving the Kremlin a needless propaganda victory.

Prime minister has reopened the debate over whether Russia sought to influence the 2016 referendum

Andy Burnham unexpectedly reopened an old Brexit debate when he said he had been told after becoming prime minister that Russia had interfered in the 2016 EU referendum.

It was a contentious issue in the second half of the previous decade, but one that had largely been forgotten about as the UK finally adjusted to the reality of leaving the EU. Now Burnham’s comments have given the topic a fresh impetus.