Taxation in this country is very high compared with many other jurisdictions. To state the obvious, it is not only income tax, but NI, CGT, VAT, council tax, road tax, stamp duty - a huge proportion of most people's income - and then, having paid substantial taxes all their lives, another slab of income is taken away from their estate upon death by way of Inheritance Tax at a whopping 40% (most homes in London and the South East will be above the threshold, even without factoring in other assets). Even tertiary education, which used to be free, involves most students taking out crippling loans, which they pay back out of their tax - effectively a tax on higher education.
I think I am right in saying that countries which have lower overall tax rates actually collect more tax, because taxpayers consider it to be fair and don't take steps to avoid it. As others have said above, higher taxes do not proved any incentive for people to work harder, quite the contrary.
I am no great fan of Shiny Dave, but God help us if Ed gets in next year, with his promise of 'mansion' taxes etc (a 'mansion' being an ordinary terrace in Islington, for example; perhaps the occupants should boost their income by selling tickets for a tour of the home and gardens!).
Many of the wealthy French who came to flee Hollande, will be leaving, along with their contribution to the economy, and there will be other groups too.