Andy Burnham, the Mayor of Greater Manchester, has stated that evidence points to Russian interference in the 2016 vote on Britain's membership of the European Union. Comparable activity in France and Germany was also flagged by Burnham, according to the Associated Press.

On the podcast "The Rest is Politics," Burnham disclosed that, upon visiting 10 Downing Street, he had raised questions about potential Russian involvement in the 2016 vote, and that the response he received confirmed it had taken place. Podcast excerpts made public on Sunday included a comment from him noting that the government had placed insufficient emphasis on informing the public about the degree to which foreign actors were attempting to interfere with domestic political processes, and that the response to such activity had leaned too heavily on a reactive rather than proactive footing.

No specifics were shared by Burnham regarding what form Moscow's involvement took during the Brexit referendum, nor how far-reaching it may have been.

Prior to the interview's publication on Monday, Burnham told Chancellor Friedrich Merz during a visit to Germany that week about the question of Russian interference. Excerpts from the conversation indicated he put forward the view that placing such matters openly on the public record could assist voters in Germany and France in recognising that certain political activity traces back to hostile foreign powers, naming Russia directly.

Russian officials have consistently maintained, across numerous statements over the years, that interference in the electoral or referendum processes of other nations forms no part of their foreign policy conduct.

No sitting UK Prime Minister had previously gone on record to assert that Russia attempted to influence the outcome of the 2016 Brexit referendum. Burnham's remarks arrive at a moment when intelligence bodies have raised concerns about attempts by Russian actors to interfere with the UK's democratic processes.

A report examining Russian interference in UK elections and referendums was put before Parliament by its Intelligence and Security Committee in 2020. That report determined that authorities had not carried out a thorough examination of the potential influence that Russian state-backed media outlets and coordinated online accounts might have exercised over the EU referendum outcome.

Britain Unbound, a group that campaigned for leaving the European Union, told a broadcaster that Burnham's comments represented what the organisation characterised as a renewed attempt to undermine confidence in the outcome of the 2016 referendum. The panel described any overseas interference in UK elections as wholly unacceptable, while also stating that no compelling evidence pointed to Russian involvement having shaped the result of the 2016 referendum. The document went further, noting that portraying voters as having been easily misled was itself a form of disrespect toward the electorate.

Ballots were cast across the United Kingdom and Gibraltar on 23 June 2016, under the terms of the European Union Referendum Act 2015, with the electorate asked to decide a single question — whether the country should continue its membership of the European Union or bring that membership to an end, a vote that came to be known popularly as the Brexit referendum or the EU referendum. A referendum result favouring departure from the European Union translated into pressure on the government to trigger the formal withdrawal mechanism, the process that came to be labelled "Brexit."

On 31 January 2020, Britain completed its departure from the European Union, a step no member nation had previously taken in the bloc's history. By the close of 2020, the transitional arrangement had run its course, with a freshly negotiated Trade and Cooperation Agreement between the UK and the EU stepping in to frame the terms of their ongoing economic and security ties.