Ten years after the Brexit referendum, Prime Minister Andy Burnham has become the first person to hold the office openly to assert that Russian interference played a part in determining the outcome of that vote. Burnham, who stepped into the role vacated by Keir Starmer in July, has argued that Brexit delivered more damage than advantage, and has indicated an openness to rebuilding the relationship with the European Union — including, at the outer edge of that position, the possibility of rejoining.

Speaking on a podcast hosted by a well-known broadcaster, Burnham recounted raising the question upon first entering Downing Street and receiving what he described as a clear affirmative — that a connection to Russian interference had been confirmed. He offered no supporting evidence of any Kremlin effort to shape the June 2016 vote, in which the UK chose to leave the EU by 52 percent to 48 percent.

Burnham argued that voters in countries such as Germany and France deserved clearer information about the role attributed to hostile foreign states — Russia among them — in shaping political movements, particularly given the growth of nationalist parties across the UK and the EU. At his Berlin meetings, Burnham reported that Chancellor Friedrich Merz described the AfD as a party carrying demonstrable financial and organisational connections to Russia, and Burnham added that material traced to Russian origins had been working its way into the flow of German political discourse.

Burnham's position on Brexit diverges from that of former Prime Minister Boris Johnson in its orientation toward the EU — Johnson having led the campaign for departure from the bloc. At a point during 2020, Johnson stated that no evidence of Russian influence had been found.

A 2020 report from the UK Parliament's Intelligence and Security Committee concluded that no thorough assessment had been carried out into how Russian state-controlled media outlets and coordinated inauthentic online accounts may have shaped public opinion during the vote. The Committee's report additionally concluded that Russian state actors had attempted to interfere with the Scottish independence vote of 2014, a ballot in which the electorate returned a verdict against separation.

British intelligence assessments have pointed to an ongoing pattern of Russian activity spanning disinformation efforts aimed at eroding public confidence, alongside cyber intrusions, acts of sabotage, and espionage operations. Unnamed sources describe the problem as one that has grown over time, with artificial intelligence increasingly cited as a contributing factor.

Across an extended period, Russian officials have maintained that the country plays no part in influencing electoral or referendum processes abroad. In the wake of the Brexit referendum, a publication depicted a segment of British politicians as gripped by unfounded anxiety over Russia — a characterisation that went beyond what the available evidence supported.

YouGov, a polling organisation, maintains an ongoing survey asking whether the UK's decision to leave the European Union was the right one or the wrong one. Polling conducted from mid-2022 onward found that more respondents than not viewed the decision to leave as a mistake. Polling conducted over the previous month placed those expressing regret about Brexit at 60 percent of respondents, a proportion not previously recorded.

The previous month, Burnham put forward a call for cross-party agreement on Britain's future ties with the EU, going so far as to raise the possibility of running on a platform to rejoin the bloc at the next general election. Receptive signals from London drew a broadly positive response among EU officials, while both France and Spain indicated openness to strengthened relations, up to and including the prospect of rejoining.

According to Professor Iain Begg of the London School of Economics, any path toward UK re-entry into the EU would face political divisions on both sides of the negotiating table and could unfold over a period of years.