Chancellor John Healey is doubling down on Britain's public financial institutions — PuFins — handing the National Wealth Fund an extra £15.4bn on top of its existing £27.8bn, and the British Business Bank another £5bn atop its £30.6bn. Together, that is over £78bn in taxpayer-backed capital deployed through two bodies answerable to a single shareholder: the Treasury. The fiscal architecture is worth understanding. When Rachel Reeves rewrote the fiscal rules in 2024, she allowed the value of PuFin assets — loans, equity stakes, fund commitments — to be netted off against public debt. The logic: if the assets maintain value and cover the government's borrowing costs, this is investment, not spending. The NWF has promised gilt-like returns by 2030-31; the BBB cites a 3.9% five-year adjusted return. The NWF's return on equity last year was -2.6%, though it argues the clock only started. The political economy is straightforward. PuFins let a chancellor invest at scale without those numbers appearing as conventional debt. The Centre for Policy Studies calls this a "financial wheeze" that echoes PFI. The government calls it crowding-in. Both can be true simultaneously: the mechanism is genuinely useful AND it creates incentives to stretch the definition of additionality over time. The additionality test is where the scrutiny gets thin. The NWF's own impact framework concedes that "assessing additionality is not a precise science, but rather an exercise in judgment." That judgment is made internally, checked by the Treasury, and reviewed by no independent body. Two cases illustrate the risk: the BBB's £25m into Kraken Technologies, a firm valued at £6.45bn raising $1bn privately, and the NWF's lending to Scottish Power, an investment-grade utility with an investment-grade Spanish parent. In both cases, the private sector was demonstrably willing to provide the capital. The Resolution Foundation argues the NWF's capacity has "barely kept pace with inflation" despite Reeves's top-ups, and that more deployment is justified. The IFS offers a colder read: if the government follows the spirit of its own guidelines, the cases for PuFin investment "may turn out to be relatively limited." The tension between these two assessments is the story. One says deploy more; the other says the eligible universe is smaller than the capital available. State co-investment is not novel. George Osborne launched a Green Investment Bank. The NWF partly replaces European Investment Bank lending lost to Brexit. The BBB targets a genuine scale-up funding gap. These are real functions. But the absence of an OBR-style independent body to scrutinise additionality judgments is a structural gap that widens as capital allocations grow. At £78bn, the stakes are too large for self-certification. The fundamental question is whether PuFins remain disciplined instruments or become a fiscal bypass — a way to deploy public capital at scale while keeping the headline debt number manageable. The answer depends entirely on governance. The instruments themselves are sound. The oversight architecture is not yet fit for the capital flowing through it.
