That's a good point. And that could easily lead to a worse result. For instance, the cost of diesel in Germany is lower than in the UK but the price of electric

That's a good point. And that could easily lead to a worse result. For instance, the cost of diesel in Germany is lower than in the UK but the price of electricity is significantly lower in the UK than in Germany, which basically punishes electric cars (which have significantly lower lifetime emissions per km than comparable diesel vehicles) in Germany while encouraging them in the UK. This is one thing we need to pay attention to as more and more of global emissions are transportation related instead of electricity related: punishing electricity production without also properly tariffing liquid fuels could backfire by discouraging electrification of transport.