Over on LabourList today, hard-line Corbynite Chris Williamson writes that his plan for huge council tax increases on millions of homes “wasn’t the cause of my departure” as a Shadow Minister. Which leaves us to wonder which of his other unpopular and bizarre opinions might have been behind the decision. We may never know for sure, given the multiplicity of choice available.

He continues, in that article, to make the case for what he calls his “idea for a progressive council tax referendum”, which he has now chosen to “champion from the backbenches”.

Interestingly, what his plan amounts to is an attempt by the Left to produce a practical political response to the fundamental unpopularity of raising taxes.

Since 2012, when the Coalition relaxed the cap on council tax rises by allowing councils to exceed a five per cent increase on the condition that voters approve the decision in a local referendum, only one such referendum has been held. The Bedfordshire Police and Crime Commissioner tried it in 2015 – and despite the popularity of higher police budgets, his proposal was battered into a 70:30 defeat. Last year, Surrey County Council was thrown into chaos by its leadership considering a tax referendum, but eventually backed down.

The problem for the Left, and the genius of Eric Pickles’s referendum reform, is that it calls their bluff. We constantly hear that “people would be happy to pay a bit more”, that higher taxes are “the price of living in a civilised society”, and that any given tax increase is “only x pence per month/week/day/hour/minute” – and yet, given five years in which they have had the opportunity to demonstrate the supposed popularity of higher taxes, every Labour council in the country has chickened out rather than put it to the test.

He doesn’t say it explicitly, of course, but a recognition that tax rises are not as popular as Labour pretends is implicit to Williamson’s new plan. He is proposing that Labour councils should seek to exceed the cap (which has just been raised to six per cent) but simultaneously offer a sliding scale of discounts:

“…propose to double council tax and then promise full discounts to those living in band A to C, followed by a 80 per cent discount to those in band D (in effect a 20 per cent increase), 60 per cent discount for Band E, 40 per cent for Band F, 20 per cent for Band G, with only those living in band H properties paying double.”

This is, quite openly, an attempt to divide and rule. Williamson judges that he can leverage the politics of class warfare and of envy to get less well-off voters to back higher taxes just so long as they will only hit others.

Notably, he doesn’t seem to think that even that is necessarily sufficient to persuade people. His plan builds in a charming stick with which to threaten poorer households if they don’t back the proposed tax grab:

‘Compare this with the current situation in which most local authorities are planning to increase their council tax by 5.99 per cent, and it should become clear how the referendum could be won. For those in fully discounted bands, the referendum equates to a choice between a 5.99 per cent rise and further cuts to services, or a council tax freeze and a cash injection into local services. The choice is a no-brainer.’

So there it is, the new Corbynite council tax message: if you are less well-off, we want you to vote to hit your neighbours with higher taxes, and if you refuse then we’ll hit you with higher taxes. “The choice is a no-brainer”.

We are yet to see if any Labour councils take Williamson up on his “progressive” proposal. I suspect they’d have to be quite courageous to give it a go – and they’d be putting their reputation in the hands of someone who is notorious for embarrassing his allies – but if they do then we could yet see a series of council tax referendums to test the theory.

If that happens, then Conservatives and other low-tax campaigners will have to develop some new messages to address Williamson’s twist on the old tax-raising argument. Opponents of these tax hikes would do well to add arguments on social unity to the more accustomed economic case, all in opposition to a Labour Party that would be appealing even more brazenly than before to feelings of division and envy.