British Prime Minister Andy Burnham has said it is clear that Russia interfered in the 2016 Brexit referendum, marking a significant departure from the position held by previous Conservative governments.

Burnham made the claim on the podcast The Rest is Politics, saying he had asked about Russian involvement after entering Downing Street. "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," he said.

He did not disclose who had provided the assessment, what evidence it was based on, or whether the interference had affected the outcome of the vote.

Past Conservative governments had insisted there was no evidence of successful Russian interference in the referendum. Burnham's comments contradict that position directly.

A report by parliament's intelligence and security committee in 2020 criticised the government and intelligence agencies for failing to properly investigate potential Russian interference. The cross-party committee found that ministers had not sought a full assessment of Moscow's activities, despite evidence of attempts to influence British politics through Russian state-backed media and social media accounts.

The committee also noted that the government had provided no post-referendum assessment of Russian interference attempts, in contrast to the investigation carried out in the United States following the 2016 presidential election. It added that whether a hostile state had sought to influence a democratic process was important regardless of whether those efforts had succeeded.

Burnham said Britain needed to be more open about attempts by hostile states to interfere in its politics, particularly as European leaders face the rise of the far right. "These things are important now to put clearly on the record and I believe help voters in Germany and France understand that some of this politics is instigated via our enemies, namely Russia," he said.

He added: "I think we've been too much on the back foot on that, actually, and we haven't informed people sufficiently about the extent to which people are seeking to disrupt the political process from overseas."

The prime minister also said he had discussed the threat posed by the far-right Alternative fur Deutschland with German Chancellor Friedrich Merz during a visit to Berlin. Burnham said Merz raised concerns about the party's links to Russia. "One thing I did say to Chancellor Merz ... is we need to support you in taking on the threat that you face and particularly the type of politics that you're facing," he said.

Burnham said Merz told him the AfD were clearly linked to Russia. "You know, he was saying to me that the AfD are clearly linked to Russia - funded, I believe," Burnham said. He added: "There is certainly misinformation, disinformation, that is emanating from Russia into German politics."

Last month, the prime minister attacked Russian information warfare during a speech to the UN General Assembly, saying there was evidence Moscow had tried to interfere with the 2019 general election.

Burnham also recently opened the door to Britain eventually rejoining the European Union, saying his government would examine all options for the country's future relationship with Brussels.