50% tax. That's exceptionally generous of you. I'd check my accountant if I were you.
But seriously, I share some of your concerns.
And it's only going to get worse. Even the Conservatives had been saying that the public spending (and therefore the tax burden) would increase over the course of the next parliament if they were to be elected. They've only changed this due to the need to reduce our staggering level of national borrowing.
When you compare it to some other countries, the UK is not that bad (relatively of course - you may still think it's really bad). There's an article
here saying that we pay 36% of the GDP in tax, whereas Denmark pay 48%. It's quite interesting as it says people in Sweden, which also pays a huge amount in tax, seem to trust their government to give that money back efficiently. It's an interesting concept.