British Prime Minister Andy Burnham said Russia interfered in the 2016 Brexit referendum, marking the first time a sitting UK leader has made such an assertion.

Burnham made the comments during an appearance on the podcast The Rest is Politics. He explained that he had inquired about possible Kremlin involvement shortly after entering Downing Street and received what he described as a clear confirmation. "I asked the question coming to Downing Street: well, was there interference in the 2016 referendum from Russia? I've had the clear answer that, yes, there was," Burnham said.

The prime minister added that the government had been too passive in addressing foreign attempts to disrupt political processes. He linked the issue to ongoing concerns in other European countries, noting that voters in Germany and France should be aware of efforts "instigated via our enemies, namely Russia."

Burnham provided no specific details on the nature, scale, or impact of any alleged interference. Previous UK government statements and parliamentary reports had maintained that no evidence of successful Russian meddling in the referendum existed. A 2020 report from Parliament's Intelligence and Security Committee criticized officials for failing to conduct a full assessment at the time but stopped short of confirming actual interference in the Brexit vote itself.

Pro-Brexit groups reacted sharply to the new remarks. Britain Unbound described them as "another crude attempt to undermine the legitimacy of the decision that the British people made in 2016." The group acknowledged that foreign interference is unacceptable but stated there is "no good reason to believe that Russian intervention influenced the outcome" and called suggestions otherwise insulting to voters.

Burnham took office in July and has previously floated the possibility of the UK pursuing closer ties with the European Union. His comments come amid heightened tensions with Russia over broader European security issues.