Prime Minister Andy Burnham has stated there is "clear" evidence that Russia interfered with the 2016 Brexit referendum. Speaking to The Rest is Politics podcast, Burnham said he asked about possible Russian interference upon arriving in No 10 and received confirmation that it occurred.

Burnham did not specify the nature or extent of Moscow's activity during the campaign. He said Britain had been "too much on the back foot" on the issue and had not adequately informed the public about foreign attempts to disrupt the political process.

This marks the first time a sitting UK prime minister has made such a claim about the Brexit vote. Russia has repeatedly denied meddling in UK elections. In 2020, Parliament's Intelligence and Security Committee published a report on Russian interventions in UK elections and referendums but did not reach a definitive conclusion on whether Russia attempted to influence the EU referendum result. The report did criticise successive governments for failing to fully assess or counter the threat.

Burnham raised the issue of Russian interference during a recent visit to Germany, where he discussed the matter with Chancellor Friedrich Merz. He said misinformation and disinformation from Russia were flowing into German politics and called for voters in Germany and France to understand that "some of this politics is instigated via our enemies, namely Russia."

The pro-Brexit campaign group Britain Unbound rejected Burnham's comments as "another crude attempt to undermine the legitimacy of the decision that the British people made in 2016". The group said there was "no good reason to believe that Russian intervention influenced the outcome of the referendum" and called it "insulting to suggest that voters were so easily duped".

In 2020, the then-Conservative government said it was "almost certain that Russian actors sought to interfere" in the 2019 general election. More recently, BBC Verify tracked Russian-linked disinformation campaigns using artificial intelligence to create fake videos impersonating journalists and news organisations. Vijay Rangarajan, head of the UK Electoral Commission, told MPs last year that Russian deepfake videos had been "used extensively in elections around the world" and said there was no reason to assume Britain would be an exception.

Burnham announced earlier this year that the UK would establish a new centre to counter disinformation.