Facebook has refused to provide the British parliament with the names of individuals behind a shadowy network backing an extreme ‘no deal’ Brexit outcome over a government-negotiated compromise.

Since the June 2016 EU referendum vote, politics in the UK has been consumed by the question of how to implement a close vote to leave.

And last year the UK’s Electoral Commission confirmed the vote was tarnished by in influx of dark money ploughed into social media ads — with platforms such as Facebook offering an unregulated route for circumventing democratic norms.

Nor have the Brexit ads stopped since the referendum.

An unknown group, called ‘Mainstream Network’, ran a series of political ads on Facebook’s platform last year which targeted voters in key leave voting constituencies urging them to pressure on their member of parliament not to support the prime minister’s approach to seek a withdrawal deal from the EU.

Such a deal would allow the UK to leave the bloc more smoothly, with more contingencies in place to cover the exit. But legally, if no deal (and/or no extension to Article 50) is agreed before the end of this month the UK could just ‘crash out’ of the EU without any such safety net.

Unknown entities have been using Facebook’s platform to push for exactly that to happen — by paying Facebook to target leave voters with anti-Brexit-deal ads (which included the line “chuck Chequers”; a reference to the prime minister’s Brexit deal).

Last year research commissioned by a UK parliamentary committee as part of an enquiry into political advertising online spotlit the existence of Mainstream Network, estimating the unknown Facebook advertiser had spent ~£257,000 in just over 10 months.

Its Facebook pages were said to have reached between 10M and 11M people on the platform.

Mainstream Network also operated a ‘news’ website, where whoever was behind it curated pro-Brexit content and advocated for no deal being “better than partition or permanent vassalage”.

Last November Facebook policy VP Richard Allan faced questions from the DCMS committee about who is behind the ‘Mainstream Network’ Brexit ads running on Facebook.

DCMS chair Damian Collins asked for Facebook to provide details of the accounts behind Mainstream Network or if it would not to provide a reason for not disclosing the information.

Yesterday the committee published Facebook’s refusal to provide the information to the DCMS committee. Though it said it has passed some information to the UK’s data watchdog, the Information Commissioner’s Office (ICO).

“The Committee asked about an advertiser on our platform called Mainstream Network. As I noted at the time, in the event that Facebook receives a request for personal data from an entity which can legally require such information, Facebook will provide information in line with normal procedures. You will appreciate that it would be inappropriate to provide personal data of our users to any third party absent a lawful basis for such disclosure,” writes Allan.

He goes on to say that Facebook has provided “information” about Mainstream Network to the UK’s data watchdog “on a private and confidential basis”.

The ICO is investigating the advertiser as part of a wider probe into the use of social media for political campaigning.

“It is now a matter for ICO (acting in accordance with its statutory duties) to determine what they will do with the data provided to them,” Allan adds.

We reached out to the ICO to ask whether it intends to disclose the names.

“We received a response from Facebook to an Information Notice issued by the ICO. The information is under review and forms part of our ongoing investigation into the use of data analytics for political purposes,” a spokeswoman told us.

Last summer information commissioner Elizabeth Denham called for an ethical pause of the use of social media tools for political ads — saying she was concerned about the lack of transparency and the knock-on impact that could have on democracy.

In recent years Facebook has been busy making loud crisis PR noises about how it’s ‘increasing the transparency’ around advertisers on its platform — ever since the 2016 US presidential election disinformation scandal blew up, and it emerged quite how many Roubles Facebook had been accepting to allow divisive Kremlin ads to target US voters.

The company launched ‘political ad transparency’ measures in the U.S. initially, including a requirement for election advertisers to verify they are US-based.

It has also since rolled out some similar measures in some international markets — including in the U.K. where it introduced a system for disclosing political ads last fall. (Though it quickly had to rework the system after it was shown being trivially easy to spoof.)

Allan appears to intend to reference the latter measures in the concluding portion of his letter, albeit he gets the date wrong by a full year.

“I further note that as of 29 November 2019 [sic], we have required political advertisers to consent to the publication of additional information in the form of a disclaimer that they create when they go through the authorisation process. All political advertisements along with these disclaimers are made available to the public in our Ad Library,” he writes, without making it clear why that should mean Facebook can’t disclose the identities behind Mainstream Network.

The company has claimed to be working towards having a “global system” for political ad transparency.

But the reality on the ground remains highly variable, piecemeal and very far from perfect full transparency.

Nor will Facebook even come clean with the public when specifically asked to do so by policymakers, as its refusal to the DCMS shows.

Responding to the company’s letter in a series of tweets, Collins writes: “I believe there is a strong public interest in understanding who is behind the Mainstream Network, and that this information should be published. People have a right to know how is targeting them with political advertisements and why.”

2/3 I believe there is a strong public interest in understanding who is behind the Mainstream Network, and that this information should be published. People should have a right to know who is targeting them with political advertisements and why. — Damian Collins (@DamianCollins) March 5, 2019

It remains to be seen whether the ICO will release the information Facebook has provided it.

The watchdog has also so far declined to disclose the identities of several senior Facebook executives who knew about another political ad scandal — the Cambridge Analytica data breach — earlier than the company had publicly claimed it knew.

The DCMS committee published its final report into online disinformation last month, setting out a laundry list of recommendations for cleaning up political campaigning in the digital era.

The report also includes the tidbit about the trio of senior Facebook managers who knew about the Cambridge Analytica breach sooner than Zuckerberg himself (but apparently did not think to share the incident with the CEO), as well as singling out Facebook for “disingenuous” and “bad faith” responses to democratic concerns about the misuse of people’s data.

The committee’s report also calls for privacy and antitrust regulators to investigate the company.