The Guardian has reported that:

The luxury car maker Porsche is likely to take the mayor of London, Ken Livingstone, to court over plans to charge drivers of the most polluting vehicles £25 each time they enter the capital. The German sports car specialist said yesterday that the proposed rise, which will come into force in October, is "unfair and disproportionate".

And I hope, and know, they will lose resoundingly.

The right to set tax does not rest with private companies. Perhaps they should learn that.