Kudos to Sadiq Khan for considering this:
https://www.bbc.co.uk/news/articles/c14m142ze58o
I saw an article in the Grauniad on this matter earlier today and thought "Sadiq Khan would do well to take a leaf out of Mme. Hidalgo's book* on this" - and I see he has

As I drive a much smaller car now, I have grown to resent these giant, lumbering monsters and their drivers around me. You simply do not need a vehicle this big: a commenter on the BBC SYB on this says he needs one to tow his huge caravan. Well, I suspect there are plenty of 4wd estates from the likes of Volvo, BMW and Subaru that could fulfil that role admirably - good God, my old BMW was rated for towing 2 tons braked... best of all, it'll piss off some people I know at work too who are very proud of their Solihull shit.
*A former colleague of mine's Volvo V70XC (I
think I have the letters and numbers in the right order) just falls foul of the Paris weight limit, as he has learned on his visits there.