UK prime minister says Russia interfered in 2016 Brexit referendum

Speaking to The Rest is Politics podcast, Burnham said he had asked about possible Russian interference in the referendum after taking office.

"I've had the clear answer that, yes, there was," he said.

Burnham did not disclose what form the interference took or how extensive it was. He also did not claim that Russian activities had changed the referendum's outcome.

The prime minister warned that similar interference was taking place in Germany and France, saying he had discussed Russian disinformation with German Chancellor Friedrich Merz during a recent visit.

"There is certainly misinformation, disinformation that is emanating from Russia into German politics," Burnham said.

He argued that European governments needed to be more open with voters about foreign attempts to disrupt democratic processes.

In 2020, the British Parliament's Intelligence and Security Committee published a report on Russian interference in UK politics. It reached no definitive conclusion about Moscow's role in the Brexit referendum but criticized successive British governments for failing to adequately investigate and counter the threat.

A pro-Brexit campaign group, Britain Unbound, accused Burnham of attempting to undermine the legitimacy of the 2016 vote. It said there was no compelling evidence that Russian interference had influenced the result.

The UK voted to leave the European Union by 51.9% to 48.1% in June 2016 and formally withdrew from the bloc on January 31, 2020.

The BBC has previously documented Russian-linked disinformation operations targeting European audiences, including fabricated reports about Ukraine and President Volodymyr Zelenskyy.

Burnham announced plans last month for a new British center to combat disinformation, accusing Russian agencies of spreading falsehoods and exploiting public fears.