No event occurs in isolation.
1)The brexiteer politicians are exceedingly limp-wristed when it comes to forging a brexit agreement. Their commitment is extremely "fragile"
2)Putin was up for re-election just before the story broke.
3)There has been much united EU action since the story broke in support of the British stance.
4)This has enabled much babbling on about the harm to our joint security if we sever ties (if you believe that suggest you return to reading books about Janet and John)

Most exquisite timing to poke putin in the eye and make the case for abandoning brexit on security grounds.

Food for thought: We expel Russian spies, Russia expels EU diplomats.
Noe come on. who is telling the porkies here?
The story has not even evolved with any degree of credibility. They havebeen making it up as they go along. Either that or they are complete cretins.