Some of them could be the draconian prosecutors who are helping the CCP on suppressing the Kong Kong young protesters during last few years! The observation groups are concerning that if U.K. allows all BNO passport holders to enter U.K. without reviews then likely some of pro communist prosecutors will move to U.K. too.
If that happens then it could be a political disaster to U.K. democracy system! Be aware! Do not let those pro communist people seeping in! Please!
Same advice to America and other democracy countries!