This is a recurring pro-Kremlin disinformation narrative linking the UK and Russophobia with no evidence provided. Russophobia is often used in pro-Kremlin disinformation as an explanation for anyone blaming Russia for anything.
By accusing Western societies of “Russophobia”, pro-Kremlin propaganda outlets downgrade criticism of Kremlin policies and actions to being somehow irrational and not worthy of a serious reply. Read previous disinformation message stating that Russophobia is an integral part of British foreign policy.
Regarding the second part of this message about Russian involvement in Brexit, studies show that Russia had an interest in influencing the discussion on Brexit: "the day of the Brexit vote, Russia mobilised an army of trolls, which at one stage included 3,800 accounts. The fake accounts Tweeted out 1,102 posts with the hashtag #ReasonsToLeaveEU."
While the Kremlin explicitly promoted the Leave campaign, Russia-linked Twitter accounts in fact spread both pro- and anti-Brexit narratives in the run-up to the referendum to create chaos and confusion.