Re: I've never understood...
> It's called the "squeezed middle", and it is one thing that really does play badly and gets governments elected out, because the "middle" generally represents the majority of the population.
I upvoted you anyway, but this certainly doesn't get governments elected out. The tories are the party of tax avoidance; look at non-dom Ashcroft.
It's not entirely true that rich and poor pay the same for fuel. It varies a lot around the country,. London is expensive, but so are remote regions. However, in a particular region, rich and poor pay the same. In London (where I live) we have excellent public transport. Yes it's crowded at times, and I avoid it and walk where I can, but when you compare it to the west country, or northern Scotland, to provide two examples, it really is excellent. Most car journeys could easily be avoided although of course there are journeys where you have no choice.
Tradesmen who need to use a van also pay extra, but they pass that cost on.
It's not as simple as taxing income. A salary of £50K will get you a nice house in many parts of the country. Round here you'll struggle to get on the housing ladder, especially if you're currently paying £3K a month on rent.
Khan is right that there are far too many cars on London's roads. Uber's loss-leading has made it comparable to public transport so more people are using it, and clogging up the roads. Emissions or not, private car hire should be taxed and that money spent on decent transport.