But there is another party, which seems to have discovered the fire and passion that moved Labour so long ago: the Greens. Last week they revealed that their manifesto for the general election will propose a living wage, the renationalisation of the railways, a maximum pay ratio (no executive should receive more than 10 times the salary of the lowest-paid worker) and, at the heart of their reforms, a wealth tax of the kind Piketty recommends.
Yes, it raises plenty of questions, but none of them are unanswerable – especially if this is seen as one step towards the ideal position: a global wealth tax, that treats capital equally, wherever it might lodge. Rough as this proposal is, it will start to challenge the political consensus and draw people who thought they had nowhere to turn. Expect the billionaires’ boot boys to start screaming, once they absorb the implications. And take their boos and jeers as confirmation that it’s on to something. You wanted a progressive alternative? You’ve got it.
Twitter: @georgemonbiot. A fully referenced version of this article can be found at Monbiot.com