Two Brexit campaign groups under investigation for potential collusion during the EU referendum used identical datasets to target potential adverts at Facebook users.



Vote Leave, the lead campaigner for a Brexit vote, and BeLeave, a campaign group run by an activist named Darren Grimes, used identical data to target audiences, according to a letter from Facebook to the Electoral Commission that raises new questions about potential coordination between the two groups.

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Vote Leave spent millions of pounds buying targeted online advertising through AggregateIQ during the referendum campaign, pushing up against its strict £7m spending limit. However, in the closing days of the campaign, Vote Leave donated £625,000 to Grimes, who then also spent the money with AggregateIQ. At that time Grimes was regularly seen volunteering in the Vote Leave office.

Both Vote Leave and Grimes have insisted that there was no coordination between the campaigns on how the money was spent, which could potentially have broken electoral law.



The new letter was sent from Facebook to the Electoral Commission as part of its ongoing investigation into potential breaches of campaign finance rules and was published by the parliamentary committee investigating fake news. It reveals that Vote Leave and BeLeave appear to have used three identical datasets during the referendum campaign to locate potential recipients of targeted pro-Brexit Facebook adverts.

“They were the exact same audiences,” said Facebook’s Gareth Lambe, who also revealed that $2m (£1.5m) of AggregateIQ’s entire $3.5m Facebook advertising spend over the last four years appeared to be associated with the EU referendum.

In addition to Vote Leave and BeLeave, AggregateIQ ran adverts for the Democratic Unionist party’s pro-Brexit campaign, as well as another campaign group called Veterans for Britain.

The letter describes three different types of dataset that advertisers can use to reach potential audiences on Facebook:

Data file custom audiences , which allow advertisers to upload data such as existing customers’ email addresses or other identifying information so as to target them directly on Facebook.

, which allow advertisers to upload data such as existing customers’ email addresses or other identifying information so as to target them directly on Facebook. Website custom audiences , which allow advertisers to target people on Facebook based on whether they have been detected browsing the advertiser’s website.

, which allow advertisers to target people on Facebook based on whether they have been detected browsing the advertiser’s website. Lookalike audiences, which enable advertisers to target Facebook users that are likely to be interested because they are similar to the advertiser’s existing customers.

“Our investigations to date have found there was one data file custom audience, one website custom audience, and one lookalike audience that were used to select targeting criteria for potential ads during this period by both the Vote Leave and BeLeave pages,” said Facebook.

The first audience was called “50million_remains”, the second was a lookalike audience, and the third was a website custom audience called “Vote Leave instapage submissions”, which according to Facebook was based on visitors to Vote Leave’s website.



BeLeave created 16 adverts using one or more of the three common audiences on 15 June 2016, but did not ultimately run any of the adverts. Vote Leave created 2,189 adverts based on the same common audiences, and ran about half of them.



Vote Leave, Grimes and Facebook did not respond to requests for comment prior to publication. The Electoral Commission declined to comment, citing its ongoing investigations.

Separately, it was reported on Tuesday that the US Department of Justice and FBI were investigating Cambridge Analytica, the data firm revealed to have obtained millions of Facebook data profiles.



The New York Times said that prosecutors had sought to question former employees and banks as part of the early stages of an investigation into the firm and “associated US persons”. Cambridge Analytica declared bankruptcy earlier this month, saying media attention had rendered the business unviable.