Landlords are aware there is subletting going on, so not sure whether that's also grounds for renewal they may use along with the ASBO.Depends how long the tenancy is.
The biggest weakness of S8 as I understand it is getting people out for anti social behaviour (which is going to be buffed up when they drop S21), so usually S21 gets used instead, but S21 date cannot be during a tenancy period.
If you lucky it might just be a 6 month tenancy or rolling tenancy, if its the latter S21 2 months notice can be given.
Couple of years back I had a real messy tenant move in to the flat behind mine at back of house, constant uber eats at my door for them, several bags of rubbish left on pavement all week, after a few weeks of that, someone from council turned up, and issued a fine, I explained which property it was and it went to the LL, suffice to say that pretty much assured they were not getting renewed so gone within a year thankfully.
Just noticed the post about sub letting might be used as a reason for S8, agree with that as well.
Is subletting usually an additional clause in agreements? I wouldn't presume it comes as a standard allowance in your general letting agreement right?