The top 2% already pay a marginal rate of 50% on income. Last time a government tried higher tax rates many top earners just went overseas and we lost their tax income altogether.
I used to work extra hours and strive hard to earn bonuses until I got fed up of losing 40% of my bonus through tax. I decided it wasn't worth it and chose instead to work less and spend more time at home.
Taxing the banks more. Mmm. Sounds like an easy solution. But when banks make profits they already pay corporation tax at the same rates other companies pay tax. And of course the state owns a large share of some banks so profits increase the value of the state's share- so we benefit.
Imposing higher tax rates on banks could have unforeseen consequences- increased charges for customers, reduced share prices (reducing the value of the governement's share) or lower net profits for reinvestment.