On the point made that It's also worth noting that the top 1% of earners contribute 30% of income tax revenue. Whilst we should be fair, we shouldn't be whacking higher earners anymore in my opinion.
Income tax only represents 27% of government income, I doubt that the contribution of the wealthiest through the other big earners of National Insurance (where you only pay 2% on income over £42K, but 12% on most earnings upto that point), VAT, corporation tax and business rates (which are usually passed onto customers as a cost of the business) and excise duties. But these make up twice as much of government income than income tax.
And until you can quantify how much of the nation's wealth is in the hands of the top 1%, the amount they pay in income tax is irrelevant. If, for example, they had 30% of total wealth, then they should pay at least 30% of the tax take, probably more as they have higher disposable income. I can't find a figure for the UK, but in the US it is estimated that the wealthiest 1% controls 42% of the financial wealth in the country.
And in the UK many of the wealthiest are very adept at tax avoidance, with around 1 in 10 people on £10 million or more a year paying less than the 20% basic rate of tax. If tax evasion and avoidance could be effectively tackled we wouldn't need any of the austerity cuts - they account for tens of billions of lost revenue. But it seems that the government either lacks the wits or the motivation to go after the tax that the super-rich are obliged to pay under the spirit of the law.
So the present system is not fair - the richest, especially the extremely wealthy, don't pay their full whack, so the burden falls on the rest of us through higher taxes and austerity cuts. The current government has hit my middle income family with a pay freeze for 3 years running (OH works in the public sector), a VAT increase, university tuition fees trebled and increased the state pension age by 2 years. Over our lifetime these policies will cost us around £200,000. So when the Prime Minister says his party is not for the better off but for those wanting to be better off, you can understand my cynicism. I have aspirations for my family, his policies have impeded them. Perhaps if we earned enough to benefit from the cut to the top rate of tax I could see what the government was doing for us, but we aren't, so I can only conclude that the extra pain handed out to families like mine is to subsidise tax cuts for the wealthy, whether they actually pay the intended taxes or not.