His 'tycoon tax' - i.e. ensuring the mega rich pay a minimum average tax level, is the best (albeit obvious) idea he has come up with in ages. The only problem is his party have slaughtered him for it. The ignorant tw@ts prefer a 'mansion tax' - or tax on family homes in London as it is also known. If they closed the loopholes that millionaires, foreigners and premiership footballers get away with we could all pay a lot less.
Avoidance is the problem, for sure. I'd favour making public the amount of tax actually paid by anyone receiving say, 200k a year or more. That way, you'd have a 'shaming' effect similar to what is happening with the bankers. On the other hand, if these people were actually paying their due, then that would be a morale-booster for the rest of us.