Rachel Reeves’s £25 Billion Problem: What the Autumn Budget Gap Means for Britain

Britain’s economy is growing again — just not fast enough to spare Chancellor Rachel Reeves from another difficult budget. The UK expanded by roughly 0.1% in August, keeping the economy on track for about 0.2% growth in the third quarter, but that modest rebound won’t be enough to close a fiscal hole opening beneath the government’s plans, according to analysis from FXStreet.

Where the £25 billion gap comes from

The Office for Budget Responsibility is expected to downgrade its economic assessment this autumn relative to its Spring Statement forecast, chiefly on weaker productivity assumptions. Combined with higher gilt yields and a series of policy reversals over the past year, that downgrade is projected to blow a roughly £25 billion annual hole in the public finances compared with the position Reeves described in March, per the same FXStreet analysis. A separate assessment attributes some of the UK’s recent resilience to a substantial rise in government spending — departmental budgets have grown roughly 4% in real terms — a tailwind officials do not expect to persist into the next fiscal year.

This follows an already-large tax package. Reeves’s autumn 2025 budget delivered more than £26 billion in new tax measures, according to Allianz Trade’s UK economic outlook, on top of £41.5 billion in tax increases the year before. Much of that revenue is earmarked for higher welfare spending, leaving comparatively little room for growth-focused stimulus.

The government’s counter-narrative

Downing Street has framed its record differently. In its own Spring Forecast presentation, the government pointed to inflation falling faster than expected, GDP per person growing more than projected in the original Budget, and household energy bill relief as evidence its plan is working, according to the UK government’s own Spring Forecast statement. Officials also cite the UK’s growth rate as the fastest in the G7 among European economies in 2025.

The Bank of England, meanwhile, has penciled in third-quarter growth of around 0.4% — a target that already looks difficult to reach given the pace of expansion through August and September, according to FXStreet’s assessment of the BoE forecast gap.

Why global finance is watching

For institutional investors from Singapore to Dubai, the UK’s fiscal trajectory matters beyond domestic politics. Persistently elevated gilt yields make UK sovereign debt more attractive on a relative-yield basis but signal continued fiscal strain — a dynamic that has already accelerated the migration of UK-domiciled wealth toward lower-tax jurisdictions including Singapore and the UAE (see our companion report on the non-dom exodus). A credible autumn budget, or the absence of one, will shape whether that capital flow accelerates further.