Our research shows that Mrs Justice Steyn herself inhabits an anti-Brexit echo chamber like the one she controversially ruled to be of no importance when it came to Arron Banks’ reputation. We have found her private Twitter account, the one that signalled her support for her anti-Brexit campaigner husband’s political ambitions. It followed 27 tweeters, two BBC journalists – who, for the purposes of this research, we will consider to be impartial – one anonymous account, and 24 well-known, high-profile remainers. That, to Guido’s mind, constitutes her own self-selected, anti-Brexit echo chamber.

She followed the likes of Faisal Islam, Eddie Izzard, Nick Cohen, Alan Rusbridger, Jon Snow, David Miliband, Robert Peston, David Allen Green, Gary Lineker and Rupert Myers – hard-line remainers all. The fact is that Karen Steyn does not follow a single Brexiteer, all her timeline and the information coming to her on Twitter is from anti-Brexit sources. That is the definition of an echo chamber.

This is important because it is a judicial principle that “apparent bias” arises when, even if the judge does not have an interest in its outcome, there is something in the judge’s conduct or behaviour, their interests, affiliations or their allegiances, that gives rise to a suspicion that they have not decided the case in an impartial manner.

The most famed example in recent years is R v Bow Street Metropolitan Stipendiary Magistrate, ex parte Pinochet Ugarte (No. 2) [2000] 1 AC 119, which involved the unprecedented decision by the House of Lords to set aside its own previous judgment based on just the mere possibility of bias.

In that case, Lord Hoffman, who had formed part of the 3-2 majority in the House of Lords trial which decided the former Chilean President had no immunity from arrest, had failed to declare his links to Amnesty International, which had intervened in the appeal. Not only was he an unpaid director of the charitable arm of Amnesty International but his wife had been an administrative assistant to Amnesty International’s London office for 21 years. When this emerged his fellow Law Lords held that: ‘The fact that a person has the necessary training and qualifications to resist any tendency towards bias is not relevant when considering whether there was an appearance of bias.’

In Magill v Porter[2001] UKHL 67, the House of Lords adopted the test of ‘what the fair-minded and informed observer would have thought, and whether his conclusion would have been that there was real possibility of bias.’ This is an objective test. When applying the test: ‘It will very often be appropriate to enquire whether the judge knew of the matter relied on as appearing to undermine his impartiality, because if it is shown that he did not know of it the danger of its having influenced his judgment is eliminated and the appearance of possible bias is dispelled.’

It is open to the claimant, Arron Banks, to draw this information to the attention of the Lord Chancellor when asking for the case to be set aside and reheard. The judge should, according to the Bar Standards Council rules, have recused herself because of her husband’s relevant political views and campaigning, which could arguably have prejudiced her views. The evidence of her Twitter account shows she was supportive of his efforts and she herself, on the basis of the people she follows, inhabits an anti-Brexit Twitter echo chamber…

Read her follows list, and their anti-Brexit sentiments in full, below:

1. Faisal Islam – 683 negative tweets about Brexit between June 2016 and September 2017, 46.5%
2. Eddie Izzard – Spent £36,229 of his own cash campaigning against Brexit. Called it hate-fuelled and vicious, called Brexiteers “little Englanders”
3. Emma Watson – Called on people to vote Remain on Twitter, saying there are “no excuses” 
4. Nick Cohen – Called Brexit a fantasy, “No one should be able to deny that Britain is in an economic and political crisis brought on by Brexit… It was pure propaganda: utter bullshit.” 
5. Margaret E. Atwood – Article: “On the subject of Brexit, she continues that if she could wave her magic wand she would “cause us to go back in time and maybe avoid this rash, unconsidered and badly informed moment. I think lies were told and I don’t think people thought through the consequences, because the people who did this didn’t think it was going to pass. Meanwhile, here comes the election, lucky you!” she utters, her voice thick with sarcasm.” 
6. Alan Rusbridger – Founded InFacts to “push back against what they say are “inaccuracies and twisted logic” put forward by the Euroskeptics, and to make the case for Britain staying in the European Union.”
7. Jon Snow – Said during pro-Brexit protest that he’s “Never seen so many white people in one place”
8. Bill Bailey – “We might not accept it, but we have to understand it and move on”
9. David Miliband – “Brexit is wrecking British democracy”. Called for a second referendum 
10. Hugo Rifkind – Called Brexit “a completely insane thing to do” and “shit. Of course it is”
11. The Guardian
12. The Washington Post
13. Robert Peston – 234 negative tweets about Brexit between June 2016 and September 2017, 82% 
14. The New Yorker
15. Monica Lewinsky – Described Brexit as “shit’s fucked up”
16. Caitlin Moran – Article: “‘Brexit is a big mad baby that should never have been conceived’ 
17. David Allen Green – FT. Finally conceded in 2018 that the “three legal paths to stop Brexit are blocked”. 
18. The Secret Barrister – No Tweets in favour of Brexit 
19. Gary Lineker – Backed campaign for a second referendum, came out as a Remainer. Accused Boris of “nauseating xenophobia”
20. Rupert Myers – Every tweet negative of Brexit. Article: “I can’t get over the fact that the winning side lied about a whole bunch of stuff & yet expect us to live cheerfully with the result.” 
21. JK Rowling – Tweeted: “If you truly want ‘the will of the British people’ to be implemented, you’ll be happy to have a second referendum to confirm what their will is. If you’re afraid your lies won’t fly twice and that breaking electoral law might be much harder a 2nd time, not so much. #PeoplesVote” 
22. Marina Hyde – Article: “David Cameron’s referendum on EU membership was intended to “settle the issue for a generation”. Since then, Britain has been trapped in a midsummer night’s scream that has lasted four and a half years, and has not technically actually even begun. We must hope the way to the sunlit uplands is via shit creek – because that’s certainly the direction we took”
23. Rafael Behr – Tweeted: “On a plan being hatched in the Downing Street bunker to blow up the Brexit deal, because, well, “Get Brexit Done” turns out to have been as reliable as everything else Boris Johnson says.” 
24. Alex Glassbrook – Brexit-hating, LibDem candidate husband