That is certainly one argument, and I shall talk about how, with such an attitude, the super-wealthy are cutting off their own noses, and how a progressive taxation system would benefit them as well as people like the hon. Gentleman and me, who earn far less than those who get hit by the top rate.
As the 2012 HMRC paper that examined the effect of the 50% additional rate of income tax noted,
“there was a considerable behavioural response to the rate change, including a substantial amount of forestalling: around £16 billion to £18 billion of income is estimated to have been brought forward to 2009-10 to avoid the introduction of the additional rate of tax.”
This is a massive sum which would arguably have been included in taxation had the measure been announced with immediate effect.
The most recent figures from HMRC revised liabilities up by £2.8 billion in 2010-11, £3.3 billion in 2011-12 and £3.5 billion in 2012-13. This means that HMRC says it earned a total of £9.6 billion more than previously thought from the 50p tax rate. These are of course projections of taxable income, but that makes the case for the new clause which I am pushing.