The bruising row over welfare cuts in the run-up to Rachel Reeves’s spring statement led to the Treasury being portrayed as a gang of bullies with spreadsheets, ranging across Whitehall.

Her moment in the spotlight on Wednesday allowed the chancellor to set these wrangles over tax and spend in a wider context: as a precondition for rebuilding the UK.

Reeves reminded MPs of the knock-on impact of Liz Truss’s unfunded spending splurge in 2022; and rightly highlighted the shaky global context that has resulted in borrowing costs increasing for most major economies.

Her fiscal rules were, she said, “the embodiment of this government’s unwavering commitment to bring stability to the economy”. In a swipe to her critics, she added: “There is nothing progressive, there is nothing Labour, about working people paying the price of economic irresponsibility.”

Those deep cuts to welfare were there – including an extra £500m scrambled together at the last minute after the Office for Budget Responsibility (OBR) rejected the Treasury’s initial costings.

A full impact assessment, published alongside the statement, showed the deep costs of those cuts for some of the poorest families in the UK, with an additional 250,000 people driven into relative poverty – a decision that will cast a long shadow.

As expected, the OBR has slashed its forecast for economic growth for this year, from 2% to 1% – and is concerned there may have been a permanent dent to the UK’s productivity, dragging on the economy in the future.

But Reeves was able to point to glimmers of hope, too. The OBR has assessed Labour’s planning reforms, one of the government’s most radical policies, and estimates these will boost growth by 0.2% over the five-year forecast period. It is actually expecting the economy to be larger in five years’ time than it anticipated in October.

The chancellor sought to make a positive case for the uplift in defence spending, too, stressing the government’s hopes for skilled job creation, from Portsmouth to Barrow, and the opportunities for spillovers from new technologies.

While it horrified many Labour backbenchers, the switch from aid to defence spending is helpful in meeting Reeves’s fiscal rules because defence tends to be more investment-heavy – and the chancellor’s’ rules allow her to borrow to invest.

Critics complain that Reeves has no coherent economic philosophy. To the extent that she does, it includes the fact that longstanding underinvestment is a key explanation for the UK’s underperformance.

The looser debt rule she adopted in October helps to prevent the cuts in investment spending previous chancellors tended to reach for when times were tight: what Reeves called “the Tory choice”.

On day-to-day spending, where her “stability rule” bites hard, balancing the books is much more of a challenge, and she has squeezed budgets in the later part of the forecast period. The OBR now says departmental spending will increase by just 1.2% a year from 2026-27 onwards – down from the 1.3% promised in the budget – after a 4% bump in the current year.

That looks eye-wateringly tight, and helps to explain the punch-ups already under way about June’s spending review.

Reeves highlighted a £3.25bn “transformation fund” that departments will be able to bid into, to fund productivity-enhancing projects, which are then meant to cut their costs in future years.

There is some logic to this approach. Part of the fund will help pay for the civil service redundancies package, as the government tries to slash admin costs, for example; it could also be used to fund more up-to-date IT to make services run better. But cost-cutting in public services already worn thin by years of underinvestment will not be easy.

If public services are not showing noticeable improvements in the run-up to the next election, political pressure to ease the purse strings will be intense, including from Reeves’s cabinet colleagues.

And while the chancellor was boxing and coxing to accommodate every last few million quid in the OBR’s new forecasts, and rebuild the £10bn headroom she left herself in October, the world was continuing to change rapidly around her.

Next Tuesday is “Liberation Day” in Washington, when Donald Trump will announce what tariffs he plans to slap on the world’s exports. The OBR reckons that if he kicks off a global trade war, Reeves’s painstakingly restored headroom could evaporate, once again.

She would then be back in the autumn, with diminishingly few options at her disposal, beyond raising taxes.