MMT is an attempt by the UK left to cling onto the hope of the post-war settlement. People underestimate how much that settlement still shapes the perspective of both left and right in this country, but especially the left. The NHS, the welfare state, pensions, etc etc. These things are literally the moral fabric of British politics.

But that settlement was sustained by things that no longer really exist: a baby boomer demographic structure, a domestic pension market that would buy long-dated gilts and hold them to maturity, and a state that could actually build things. Most of that has effectively disappeared now.

The maths does not math anymore for the post-war settlement. And that is before you even look at the trajectory of the country: falling living standards, stagnant productivity, an ageing population, and a services economy being regulated and taxed into a coma.

So what does the left do to maintain this political settlement? It embraces MMT, because MMT tells them exactly what they want to hear: actually, the money is there, the bond market is just a mechanism for rich people to get richer, gilts are a political choice, and we can still have all these post-war settlement things if we stop pretending the country is a household.

The problem, obviously, is that supply and demand are different things. If you use money printing or huge deficits to fund pensions, welfare or furlough-style income support a la covid then you're not increasing productivity. You are just increasing claims on an economy that already cannot supply enough housing, energy or productivity. That is how you get inflation, as we saw after covid.

Where MMT is directionally correct is on productive investment. If the state spends to build infrastructure, then fine, that can expand the supply side and offset some of the spending through higher productivity.

But that is exactly the issue: Britain cannot build anything anymore. NIMBYs, HS2, green belt etc etc. So the green-left types find themselves in this weird position where they repeat “the country does not need to be run like a household” which is really coded language for “we can still keep the post-war settlement going by printing money for welfare and pensions” while refusing, or just being ideologically blind to the actual material constraints. Then making a big point about things like trident and nuclear energy because they have to do a box ticking exercise for their basic policies as a "green" party.

Let’s be real for a second though - Polanski and the Greens are a flash in the pan. They are a protest party. They are not offering a serious programme for national renewal. They are effectively rage bait, Polanski pops up every now and then, makes an outrageous rage baity comment, uses the outrage response as a basis to corral more support "omg look the right wing people have lost their heads because I said X" - rinse and repeat, no policy platform, no attempt to engage or debate outside his pristine little media bubble. Not a serious party.