You're all missing the point here.
Tax payers who pay the 20%/40% the rest of us do, pay their fair share. The ones who exploit loopholes and pay next to nothing, like when vodafone got out if paying billions in tax are the ones you should worry about.
No richer people shouldn't pay 50% or 60% they should pay the same rates as you and I. (I'm not rich by the way).
This problem will never go away though and I'll tell you why......
Businesses run politicians, through contributions, through funny hand shakes and mostly because big politicians are share holders in big companies, so tax dodging increases their dividends.
This will never change until politics is funded by the tax payer, political contributions are made illegal, after all bribery is illegal to the rest of us.
And no political leaders are allowed to be share holders in companies or be connected to them.
Then and only then will everyone pay equal tax contributions as we all should for the good and benefit of society.