It’s all a pile of nonsence. A ‘congestion charge’ isn’t really a congestion charge if there are opt outs for greener vehicles. And the wealthy drivers who tend to own more polluting vehicles will simply absorb the extra cost. Besides, the main polluters are the many in their Focus, Golf, Jazz, Almera, etc, and not the few who buy Porsche Cayennes or BMW M5’s.
Although I haven’t checked this, I’m quite sure many new small cars on the market today would easily qualify for the 100% Ken-gestion charge discount. Those who own these cars are simply going to start taking the car instead of the bus or train when this kicks in. I know I would if I was in that position, although any incentive to avoid using London United buses or South West Trains.