Emails unearthed by a British academic and OpenDemocracy.net suggest that former Trump White House advisor Stephen Bannon and Cambridge Analytica, the data firm that employed him, advised the “Leave.EU” campaign and raised money for it.

The emails date back to October of 2015, when Bannon was the vice president of Cambridge Analytica, a firm funded by American billionaire Robert Mercer, a top donor to Donald Trump’s US presidential campaign. OpenDemocracy and Emma Briant, a professor at the University of Essex, have submitted the emails as evidence to British officials investigating the role that propaganda played in campaigns to convince British citizens to vote to leave the European Union.

British politicians have noted the similarities between the “Leave” campaign’s social media strategy and the Trump presidential campaign, and suggest that Bannon’s links to the two are part of a global strategy to upset liberal democracies.

“There are direct links between the political movements behind Brexit and Trump,” Damian Collins, chair of the parliamentary committee investigating disinformation and fake news, told the Guardian. ”We’ve got to recognize the bigger picture here. This is being coordinated across national borders by very wealthy people in a way we haven’t seen before.”

He’s now calling for a “proper Mueller-style investigation” in Britain.

Britain, like the US, bans foreign contributions to political campaigns, and British officials are investigating whether Leave.EU campaign founder Arron Banks illegally used Cambridge Analytica. British elections have hard spending limits, and there are questions over whether Leave.EU violated campaign laws by allegedly using Cambridge Analytica’s services as a gift, rather than counting the value of those services against its spending cap.

Banks has said publicly that Cambridge Analytica was never awarded a contract by the Leave.EU campaign, and that the only data he sent the firm came from UKIP, the British pro-independence political party. But the recently unearthed emails contradict his statements. OpenDemocracy says it has communications that “indicate that the former Breitbart chief [Bannon] introduced Banks to Alexander Nix, Cambridge Analytica’s onetime CEO, and arranged a follow-up phone call between Banks and Cambridge Analytica.” It did not publish those communications, but it did publish emails that seem to have been written afterward.

In an email dated Oct. 24, 2015, Banks writes to other “Leave” campaigners and backers, and to Bannon, that he would like to get Cambridge Analytica “on the team” and “come up with a strategy for fund raising in the states.”

OpenDemocracy.net

On Nov. 2, 2015, Cambridge Analytica’s CFO writes to Leave.EU campaigners, cc-ing Bannon, with the company’s proposal to provide “data analytics and creative support” to the campaign:

opendemocracy.net

In an email on Nov. 24 that year, a Cambridge Analytica employee asks Leave.EU campaign employees for data of people who have signed up on the campaign’s website or called into its call center:

OpenDemocracy.net

In another email that OpenDemocracy says was sent that November (the exact date wasn’t disclosed by the group and there’s no time stamp on the email), a Cambridge Analytica employee writes Banks that it “was a pleasure to work with your team last week for the launch and planning for the future of the campaign.”

opendemocracy.net

The Leave.EU campaign launched in September 2015. Together with the “Vote Leave” campaign, it used social media to push the idea that leaving the European Union would be an easy-to-negotiate break that would save Britain money, which has not proven to be true. In the June 2016 Brexit referendum, British voters narrowly supported leaving the European Union, 51.9% to 48.1%.