I've read the letter now. Actually I do think that at least several signatories to the letter (witnesses) are lying when they state;
'The accusation that we are politically motivated is false.'
One of the signatories lost the plot on a rejoin-EU Facebook group shortly before Christmas - in fact he regularly posts on multiple rejoin-EU Facebook groups, e.g. I've found him on: Reunite EU - British EU Rejoiners, European Movement UK, Rejoin EU, The British Pro-European Political Blog, The Very Brexit Problems Club, Fife4Europe, Cambridge for Europe [Top Fan], Leeds for Europe... -
despite him telling ITV in an interview that he 'didn't have any political affiliations at all'.
Some extracts from his disagreement/ranting on-line before Christmas (in no particular order):
'Fraid that’s crap from you too. What you believe is what you dream up when your hands are not typing. None of us or any paper or tv outlet have heard anything. And how many times have I got to tell you to read up… ?? I am a named person, have been since 3 weeks and was on itv yesterday three times on all news broadcasts. Jeepers. Nothing like discussing with an oaf who can’t even read up, but spouts utter drivel, continuous. Like I said, pipe down. You’re just proving to all and sundry what a dimwit Reform voter sucks up as fact and spews forth. Thanks for that, I guess'
'Sorry. If you're going to come on here and talk twaddle - then face facts, or become a coward like you like to bandy about concerning everyone else. Thing is, I know NF. We went to school together. In the same class. I know the people he bullied. Read up, won't you. So telling me to have a proper debate and simultaneously spouting your fragile grasp of uncorroborated statistics really is risible playground material. What you have clearly not a dickiebird clue about is that your hero - who caused the sea of economic and social problems - is the problem the country has. No good you twaddling on about labour this, tory that, IMF, price and incomes policies, ted heaths power cuts, the oil crisis, des healeys nationalisation, Maggies poll tax, etc etc - your idiot hero caused the mess that we are living in NOW. And he wants to fix it?? Please, just pipe down and keep quiet. That way you don't have to expose to people that you really are daft as...'
'Thankfully, the coward that is NF hasn't made it to PM since then you'd need to be privately insured and will cough up handsomely...'
'and then there's all the money he's taking from abroad... which when trickie Dickie Tice went on about how unfair it was that George Soros donated to his opponents, twaddled on about how unfair it was.'
'Jesus… you really are thick as a pile of 4x2. Do you read anything? Can you even? Do you have the capacity? Everything you’ve stated, or dreamt, I’ve proven false. What a pathetic example you are. Drink some Horlicks and go to bed. When you’re sober, re-read. Leave the meths alone...'
'hahahaha. Keep on repeating. Facts in tatters. Reason - gone. Love to see roasted gaslighting gammon Maybe have a glass of wine, might give you some solace. Enjoy your band of proven traitors.'
Another signatory to the letter regularly reposts anti-Brexit, anti-Tory and anti-Tory stuff on X - e.g. 16th December he reposted;
'Fucking finally. I hope the Tories and Reform traitors are shitting themselves. We still need a proper http://Leave.EU investigation. The Tories “did not want to know” if Russia interfered in Brexit. Probably because they all profited from it.'
In light of the above I think it would be very difficult for several named witnesses (at least) to claim that they were not politically motivated - therefore several lied signing that letter.