Just so its clear to punters not aware sex parties are brothels and illegal, the Police can raid and close them at any time they wish to. Whether they will or not is the question, they have never turned up while I was at a sex party. A punter attending a sex party that has all willing WGs who are adults is not breaking the law by going. IF any WG was proved to be being coerced/forced, underage, trafficked the punter could get done. WGs not actively helping the pimp/s run a party like taking punters calls and booking them in also aren't breaking the law, its the pimp/s who run the party who are. But if a WG or more than 1 decide to run a sex party themselves they then could get done for running a brothel.
BUT now during Covid they could fine punters who attend if they exceeded the max number of people allowed to meet, and any other rules regarding Covid that are subject to a fine.
Years ago now GP parties that I went to a number of times got raided and closed later and the 2 pimps who ran it got convicted of various offences, they were in East London at the time. This wasn't an isolated case, a couple of other parties also got done in London. So it has happened in the past and could happen again at any time. The standard of evidence the Police require to raid and close is send a copper in posing as a punter and as soon as he gets offered sex he leaves and that is enough evidence needed, simple.
My advice to punters is wait for Covid to improve before considering mixing with loads of strangers at a sex party, punting 121 is enough of a risk for my liking, but as ever punters will make their own minds up of course.