Back in 2007, when the Tories as much as Labour assumed that boom and bust had been abolished, George Osborne told  his party's conference that a Conservative government would raise the inheritance tax threshold to £1m. It was unacceptable, he said, that a tax "designed to hit the very rich" was increasingly borne by "ordinary people". The pledge was a political masterstroke, prompting a surge in support for the Tories and spooking Gordon Brown into abandoning plans for an early election.
But the policy looked less impressive by the time of the general election when Osborne's declaration of an "age of austerity" sat uneasily with a pledge to cut taxes by £200,000 for the wealthiest 3,000 estates. The Chancellor, according to Janan Ganesh's recent biography , was secretely glad when the Liberal Democrats gave him political cover to abandon the pledge.
In last year's Autumn Statement, he announced that the inheritance tax threshold, frozen since 2009 at £325,000 (£650,000 for couples), would rise by a paltry 1 per cent in 2015-16 to £329,000. Now he's set to announce that, in fact, it won't rise at all. Instead, to help meet the £1bn a year cost of the coalition's social care plan , the threshold will be frozen at £329,000 until at least 2019. Many more "ordinary people", to use Osborne's phrase (although the average house price is £249,958), will be hit by inheritance tax. Were the threshold to rise in line with inflation, it would stand at £420,000 in 2019.
In other words, Osborne is effectively increasing the tax - and he is right to do so. If "equality of opportunity" is to be more than merely a slogan, a progressive inheritance tax system is essential to prevent privilege being automatically transferred from one generation to the next. As Warren Buffett sagely observed when he campaigned against George W. Bush's plan to abolish "the death tax", one would not choose the 2020 Olympic team "by picking the eldest sons of the gold-medal winners in the 2000 Olympics". It would, he added, replace a meritocracy with an "aristocracy of wealth". Inheritance tax is currently levied at 40 per cent; a progressive government would consider introducing a higher band for the wealthiest estates.
Osborne's U-turn may have more to do with his desperate need for revenue than any conversion to progressive taxation but it is an opportunity for Labour to finally make the principled case for the tax.