The poorest do not make the biggest contribution to income tax and NI revenue, rov, neither in absolute terms nor in percentage terms. In 2011-12 the percentage deductions for income tax and NI for people on various salaries is as follows:
£10,000 8.38%
£12,600 13.25%
£20,000 20.19%
£50,000 28.79%
£100,000 35.39%
£200,000 42.69%
£1,000,000 50.14%
So you can see that a worker on the National Minimum Wage (£12,600) is left with about 87% of his pay, whilst the banker on £200k is left with less than 58%.
If the 50% rate is abolished and the changes to basic rate and higher rate allowances go ahead as suggested all of the salary amounts I have shown will see an increase in their retained income. Of course those earning £150k plus will benefit most, but that’s because they are currently being taxed punitively for no reason other than political point-scoring.
Anybody with any sense does their best to minimise their tax bill. Those paying the most will do the most in that respect. All power to their elbow. I’d do the same if it was worthwhile. Instead of finding ways to increase revenue the government needs to concentrate on reducing expenditure. It is not doing so. All it is trying to do (not very successfully) is to reduce the rate at which expenditure is increasing.