Re: Answering a few points in the comments...
"Our EV works out cheaper by far than the car it replaced. We pay less now including the repayments for the car and all fuel and servicing, etc. than we did for just the fuel on the car it replaced. The EV does very similar miles to the old car."
Yes, but that is because you are being subsidised, and the petrol/Diesel buyers are being taxed to fund it. An article yesterday said that because there's less tax coming in via fuel duty and VED, people are talking about road pricing again, everyone's hated bollocks. It's reared its ugly head again because LEV are eating the tax man's lunch, and the reality is life will have to get a lot more expensive for you.
If you do 10k miles/year, in a car that does about 50 mpg, then you buy about 200 (UK) gallons of fuel, costing about £5/gallon, of which about £3 is tax (it's slightly more, but whatever). So such a car pays £600/year to the Exchequer, plus VED, another £100/year or so. So each electric vehicle is avoiding roughly £700/year in tax. These are rough figures, but you get the broad idea.
That money is needed, both for the road network but also for everything else it subsidises, like the NHS, schools, HS2, Trident replacement, and bungs for the DUP. Since it would be politically difficult to stick the cost on electricity directly, expect an electric vehicle tax of at least £500/year by 2030. How does that make your calculations on upkeep look?