I have to say it’s quite interesting to see the sort of language that people use around Labour’s proposed fiscal rules, and how they perceive that what’s proposed won’t equate to austerity, simply because it will be a Labour Chancellor. The facts don’t back that up.
The key fiscal rule proposed by Reeves is exactly the same as is currently in operation, namely for government debt to be falling as a proportion of GDP by the fifth year of the forecast horizon. The only commitment here is for there to be a projected decline, rather than actually achieving it, and given that it’s a rolling projection the fiscal rule effectively can’t be broken as long as the OBR forecasts a decline five years’ out. But this flexibility around the rule will be the same under Reeves as it is currently.
The secondary part of Labour’s rule is for the current budget (headline borrowing minus investment) to be in balance, although there’s no timeframe around this. In theory this allows for investment to rise within the framework, but the fiscal rules operated by Hunt right now also allow for this. And any increase in investment will still be constrained by the overall need for debt to be seen as falling in five years, the same as under a Conservative or Labour Chancellor.
So the flexibility on investment will be very limited, and balancing the current budget will be extremely difficult. It’s running a deficit of 2% of GDP now and given that Labour are ruling out major tax hikes, spending growth on departments etc will remain very weak. If anything the current budget aspect of Labour’s plans, if they implement it, actually makes austerity around departmental spending and welfare over the next parliament more likely than what we have now.
There are plenty of economists who disagree with you, so there's not a huge point in discussing "facts" because the facts support multiple readings. Economics is fascinating, but it's part science, part politics, and the maths generally gets bent to the will of the politics, rather than the other way round.
I also think 'austerity' has become so ubiquitous, and applied to so many situations, that it's almost meaningless. Anyone who doesn't say they're going to push up taxes, or nationalise every industry, or immediately increase benefits is apparently exactly the same as George Osborne.
Osborne's "austerity" was a specific policy of deliberate cuts to the state. He was quite open about wanting to cut the size of the state, because he believed it would unleash the private sector.
I wouldn't even put Jeremy Hunt* in that category, never mind Rachel Reeves.
*Hunt has argued that the state needs to shrink to avoid(!) austerity, which is probably a good example of how "political" economics works.