Britain officially declared Wagner a terrorist organization on Friday after announcing it last week.
This fact makes it illegal to be a member or support it.

In particular, on his website of the British Home Office, it is reported that “the Russian mercenary organization Wagner, is designated as a terrorist organization today (September 15) following an order of Parliament on Wednesday (September 6).

According to the British ministry, the order comes into effect immediately, making it a criminal offense to be a member of Wagner or actively support the team in the UK and carries a 14-year prison sentence.

Wagner is now on a list of 78 terrorist organizations banned in the UK.