British Prime Minister Andy Burnham says it is clear that Russia interfered in the 2016 Brexit referendum.

Burnham told The Rest is Politics podcast that he raised the question when he arrived at Downing Street. "I asked the question coming to Downing Street," he said, and he got a clear answer that there was interference.

It is the first time a UK prime minister has said publicly that Russia meddled in the vote to leave the European Union. Past Conservative governments said there was no evidence of successful interference.

Burnham did not say who gave him the answer or what evidence it rested on. He also did not say whether the interference changed the result.

"I think we've been too much on the back foot on that," he said, adding that Britain had not told people enough about efforts to disrupt its politics from overseas. He said similar efforts are happening in France and Germany. He said he discussed Russian disinformation with German Chancellor Friedrich Merz in Berlin last week.

A 2020 report by Parliament's intelligence and security committee criticized the government for failing to properly look into Russian meddling in the referendum. The report found that ministers never asked for a full assessment.

Britain Unbound, a pro-Brexit group, called the remarks "another crude attempt to undermine the legitimacy of the decision that the British people made in 2016." It said there is "no good reason" to think Russia changed the outcome.

The outlets differ on timing. The BBC says the interview was due out Monday. Al Jazeera says it was released Sunday.

What we know: Burnham says officials confirmed to him that Russia interfered in the 2016 referendum.
What we don't: What evidence supports the claim, how large the effort was, and whether the government will publish an assessment.