Thanks for letting people know that the UK chapter is sending this letter.
It is a shame that so few Wikimedians in the UK have contributed to the process, I think it is correct to say that even after counting employees and trustees, the number is fewer than could be counted on the fingers of one hand.
I am assuming that the UK charity is open to receiving feedback, though your email here, nor your equivalent notice on the UK wiki does not invite comment. My apologies if my assumption is unfounded, please ignore the following points if that is the case.
Three points: 1. I note that the letter appears to state that the Free Knowledge Advocacy Group EU is a UK charity, it might be an idea to get the prose slightly more specific.
2. The lead paragraph states "We are the UK based charity that supports and promotes Wikipedia and its sister websites such as Wikimedia Commons". This is quite different from the WMUK Mission as recently approved by the board of trustees which does not mention Wikipedia or Commons. I suggest that in an official letter of this type, that the charity is described as accurately as possible, even in a plain English summary.
3. Were I the recipient I would be unclear if in emailing back, I were responding to the WMUK charity or the Free Knowledge Advocacy Group EU. The Royal "we" used throughout the letter is more than a little confusing as it is signed by the CEO of possibly either (or both) of WMUK and the Advocacy Group and correspondence email is a different personal address. Is the letter intended to be from the UK charity or the group of organizations in the Advocacy Group?
Good luck with the letter. I'm sure that Jon Davies' practical experience in the world of politics will prove useful if any MEP would benefit from a follow-up, such as a discussion over lunch.
Fae