I would hate to think how much of your average Brit's gross income disappears in tax - DIRECT tax at that, no choice in the matter, unless you're rich enough to exploit a few loopholes like many do - including MP'S
 
Now, if you want to talk about INDIRECT tax, this is where VAT @ 20% comes into play, as theoretically, you can avoid paying it. But you wouldn't end up buying very much stuff. The difference between us & US is that the advertised price in a store is what you pay - VAT is included in all prices. Online retailers sometimes show both, as businesses can claim what they pay on their purchases (Import Tax) and reclaim it on the VAT they charge their customers (Output Tax).
 
I really didn't want to bring the amount of tax we pay on petrol (gas) into the equation, but we pay an absolutely HUGE sum of money to the government. I'm not sure how much of the £5.90 - yes FIVE POUNDS 90 PENCE a gallon is for the duty, but it's in the region of about at least 50%