We live in an age of stunts and soundbites so it was refreshing to hear a politician stand up and, for the best part of an hour, explain their political philosophy to an audience savvy enough to shred it. That’s what Labour’s Rachel Reeves did at last night’s Mais lecture.

She summoned the ghosts of heterodox leftists Karl Polanyi, Joan Robinson and Marie Curie to explain that Britain stands on the brink of a global economic regime change just as big as the one begun in 1979, that the Tories have left us bystanders, and that Labour is the only party that can make it happen.

Though she didn’t mention Margaret Thatcher by name (and never planned to, I understand) the speech, and the fiscal rules it outlined, has generated ‘Iron Lady’ headlines. But if we look behind these, there are five takeaways that embody the logic of her argument.

Reeves is telling the OBR to adopt a new, or at least more analytically diverse, approach to fiscal modelling

1. What’s wrong? Reeves believes the neoliberal economic model is broken. She doesn’t use the word ‘neoliberal’ because it’s left-speak, but that’s what she means: globalisation in its old form is dying and economic strategies framed around expectations of stability won’t work.

Instead, we’re living in a new age of insecurity driven by geopolitical instability, technological change and the climate crisis. ‘There is no viable growth strategy today,’ she said ‘which does not rest upon resilience for our national economy and security for working people.’ In case it’s not obvious, that is the antithesis of the assumptions behind Blairism.

2. What’s the solution? This was not the first time Reeves has outlined her ‘Securonomics’ strategy, focused on investment-led growth, but it was the most detailed. Labour knows that the high tax take, together with high debt and high debt servicing costs mean there can be no return to ‘borrow-and-spend’ unless the economy achieves sustained growth.

To trigger it, it will use the suite of policies associated with Bidenomics: clear, long-term signals of government intent, accompanied by multi-year Treasury settlements, a planning revolution and regulatory change to encourage pension funds to invest in UK entrepreneurship. It’s been dubbed ‘Bidenomics without the money’ but unfairly: the money that’s fuelling the infrastructure, green energy and semiconductor boom in America is capital, not tax dollars. What’s making it happen is judicious use of incentives, guarantees, loans and subsidies – but above all certainty.

Reeves understands – because it has been explained to her over hundreds of stale croissants – that global businesses need stability. Her jibe at the Tories – five prime ministers, seven chancellors, 12 plans for growth – would have hit less hard if there had been a consistent political economy underpinning Conservatism during these years.

What Labour is promising is a comprehensive de-risking of investment in priority areas: clean energy, green steel, advanced manufacturing, life sciences and – I would hazard a guess, given its salience in Reeves’ speech – security and defence.

3. What does it mean for fiscal policy? The headline Reeves’s team briefed was that the Bank of England will see both the Monetary Policy Committee and Financial Policy Committee regain their duties to pursue net-zero objectives. But the real zinger concerns the OBR. Reeves effectively offered markets a trade-off. She set out the same broad fiscal rule as the government: debt falling at the end of five years and a deficit moving towards primary balance. She will make it law that any fiscal decision by government will be subject to an independent forecast of its effects by the OBR. But, she said:

‘I will also ask the OBR to report on the long-term impact of capital spending decisions. And as Chancellor I will report on wider measures of public sector assets and liabilities at fiscal events, showing how the health of the public balance sheet is bolstered by good investment decisions.’

Why is this so big? Because the OBR does not currently model the ‘long-term impact of capital spending decisions’. It believes that £1 billion of new capital investment produces £1 billion of growth in the first year, tapering to nothing by year five. Furthermore, since 2019 it has repeatedly expressed scepticism that a sustained programme of public investment can produce a permanent uplift in the UK’s output potential.

Since that is precisely what Reeves plans to do, she is telling the OBR to adopt a new, or at least more analytically diverse, approach to fiscal modelling. And she is signalling that the Treasury will start weighing the assets created by borrowing, alongside the liabilities.

As I say, this is not just a message to the OBR, the Treasury and the Bank. It is a message to investors: if Labour can demonstrate, through professional analysis by these institutions, that investment can drive growth, it can win the argument with fund managers for investment here and meet its own fiscal rules more easily.

4. Will it work? Reeves spent a lot of time detailing the institutional framework she wants to use to make investment-led growth happen: the British Infrastructure Council, a restored Industrial Strategy Council, the National Wealth Fund, ten-year R&D funding cycles for government departments.

But in the end it will all be about execution. For me, as a believer in this new approach, the question is how Reeves will react to adversity. Say she sweeps away planning rules that block solar farms, pylons and battery installations but the National Grid still drags its feet, and capital doesn’t come fast enough: what then?

My worry about Labour is that it has convinced itself that de-risking is an easier strategy than borrow-and-spend when – in an economy stripped of dirigiste institutions – it is actually harder and might need more radicalism, not less. Once you’ve faced down the Nimbys and your brand new solar farm is waiting a decade for a grid connection, do you have to nationalise the Grid?

5. What about the workers? Reeves gave a cogent explanation of why employment rights will lie just as centrally to Labour’s project in government as green growth. ‘There is now a wealth of evidence that greater in-work security, better pay, and more autonomy in the workplace have substantial economic benefits’ she said.

That’s why Starmer’s Labour is determined to work in partnership with the unions, and more importantly encourage business to do so.

I am certain the unions will want more. Indeed, I expect one of Reeves’s early challenges will be the return of wage-push inflation in certain sectors. Not because unions are strong in, for example, advanced manufacturing or civil nuclear, but simply because there are not enough tech graduates and skilled production workers to go around.

But in the end, this is – again – not Blairism. Unions like the GMB, USDAW and Unison have played a central role in shaping Starmerism and, though they’ve had to lose certain cherished policies, getting their main one – employment rights from day one – into the text of the Mais lecture is a marker.

In summary, what we saw last night was a plan. It’s coherent, well founded in economic theory and expresses a clear political philosophy: that social and climate justice have to be delivered in partnership with capital, that capital will need clear long-term incentives, and that the national interest and workers’ interests coincide.

Reeves has emerged from five years in opposition as a stronger and more coherent political voice, which – given she was refused the job in Starmer’s first shadow cabinet – is an achievement. But now comes the hard part.