The list today is
Birmingham, Bristol, Glasgow, Oxford, Bath, Bradford (not cars) and Portsmouth (not cars). People forget the London commercial vehicle LEZ has operated for a few years, my son got a 250 fine and a colleague 1000 (a German with a German registered land rover), in both cases the fines were large as they didn't realise they were due and missed the payment deadlines.
I picked up a £27.50 charge taking my A2 TDI to my mums...because I was in a hurry and I decided to just pay, in all these cases I can assure you we won't be taking our Diesels into London again. £8 for Birmingham...well I'll save that cost in fuel by taking my A2.
Coming for sure Edinburgh, Dundee, Newcastle, Sheffield (trucks only).
Manchester and Cambridge are talking about it.
I'm off to Brussels soon, there they have it but in Brussels you have to pre-register and get a sticker (again common in Europe) and you get fined for no sticker (or the wrong sticker) and you may not be allowed in on some days depending on the sticker your car gets. Brussels also has a rolling tightening with Euro 4 petrol (like our A2's) being subject to a penalty from 2030.
It's coming, I was in the London zone today and its noticeable how many vehicles are now electric and TBH the local air quality was better. I know that isn't true everywhere in the zone either, I may have been lucky. Compared to my school days beside an urban dual carriageway the air quality is so much better, but Cats and Euro 1 made a huge difference and they came in in 1992.