Like so many other current economic puzzles, the redistribution of income from Labour to capital can be largely explained by the entry of China, India and other emerging economies into world markets.

Labour is already planning to raise nearly 1% of GDP from higher national-insurance contributions and a tax raid on higher earners, including a top rate of income tax of 50% from April 2010.

Norway dramatically cut top rates on both labour and capital income in 1992, from a 58% top income-tax rate to 28%.