What about builders, Ford are producing electric Transits but they won't tow a 2 tonne digger on a trailer. I did read an article where someone towed a caravan behind a full electric vehicle (sorry can't remember what vehicle) and only got 54 miles per charge. So what provision is there for when ICE is banned ?
Yep, apparently the rule of thumb is that towing with an EV up to its rated capacity will halve the range.
As for provision for when ICE is banned, that's decades in the future. There will be loads of diesel transits and suchlike around for yonks and yonks, AIUI the proposed ban on ICE vehicles in 2030 only applies to private cars, not commercial vehicles like vans, pickups, and trucks which do 99.9% of commercial towing.
The Ford F150 Lightning has a towing capacity of around 4 tonnes and a max range of up to 320 miles, and that's for the current version. I can't imagine they won't be able to improve on that over the next 10 to 20 years.