It's appallingly misguided, of course. The motorways and roads are clogged, the railways aren't getting much better and the government is really trying to present this as a sop to the green lobby when all it really is, is an attempt to fill government coffers (probably to try and fix the railways).
If they are so concerned about the environment, why not answer this question? What is the most environmentally efficient way to move 180+ people. Can't tell them not to travel - so how about 180 cars? Diesel trains? Coaches? Get real. The efficiency and environmental friendliness of aircraft when compared to other forms of transport (there aren't many electric trains in the UK) is not bad and if they do want to improve, the way is not to tax airlines, it's to put money into research and provide financial incentives for airlines to use the most efficient engines - most do already.
One report commented that the aim was to try and stem the growth in low cost travel - as if it were a bad thing. How many jobs is that going to cost? Low cost is the way forward, whether the government - or the neo Luddites, greens or whatever they want to call themselves - likes it. If they want to go ahead with this nonsense, fine - the airlines will move out and other European countries will benefit.
Personally, I doubt if this will get through, but if it does, will be a disaster for airlines, jobs, transport generally and ultimately, the economy.
