MI5 chief confirms Russia tried to interfere in the Brexit referendum

Russia did try to interfere in the 2016 Brexit referendum, the head of MI5 has confirmed, but he said the attempts had little effect on the result.

Ken McCallum, director general of the domestic intelligence agency, was speaking at his annual threat update. He backed comments made by the Prime Minister, Andy Burnham, who had raised the issue over the previous two days.

TV and trolls

McCallum said the Russian-owned English-language broadcasters RT and Sputnik "came in pretty strongly around the time of the referendum" with biased anti-migration and anti-EU reports. There had also been "a second line of interference attempted through trolls": fake social media accounts, mostly on X, trying to sway the vote.

Neither was particularly sophisticated or successful, he said, adding that there was a big difference between "what may have been attempted and what actually resulted".

Both forms of interference had been described in studies after the vote. One analysis found RT and Sputnik published 261 mostly misleading articles that achieved 134m potential page impressions.

"Up to us how far we allow our adversaries to divide us"

McCallum warned that continuing to argue about the issue risked giving the Kremlin a propaganda victory. "It is up to us how far we allow our adversaries to divide us," he said.

"I'm a little bit worried that if we all stay in this debate for another few days, the Russian trolls who didn't appear to do all that much at various points over the years, they'll be delighted they are front-page news once again."

How the row began

Burnham raised the issue in a podcast interview at the weekend. "I asked the question coming to Downing Street: 'Was there interference in the 2016 referendum from Russia?' And I've had the clear answer that yes, there was," he said. The next day he stepped back when the Conservatives asked whether he regarded the result as illegitimate.

Downing Street said it had been confirmed that Russia interfered in the 2019 general election, and that it was "inconceivable that they didn't in 2016", but added: "We don't believe it was successful in the British referendum in 2016."

The row comes as Burnham has promised a "serious dialogue" about the UK's relationship with the EU, while saying the public would be "the boss" in any decision about closer ties.

Other threats

McCallum also warned that rightwing extremists were increasingly likely to consider terrorist attacks, and described a growing mix of threats facing the UK from terrorism, hostile states such as Iran and Russia, and the misuse of artificial intelligence. MI5 says the public can help by reporting suspicious activity to the police or through the government's anti-terrorism hotline on 0800 789 321.