The UK government borrowed £23.3 billion in May 2026, overshooting the Office for Budget Responsibility’s forecast by £5.6 billion and marking a 30.4% jump from the £17.9 billion borrowed in May 2025.

The Office for National Statistics published the figures on June 19, and the headline driver is hard to miss: central government debt interest payments hit £11.7 billion for the month. That’s a 54% increase year-on-year.

Where the money went

Public spending reached £118 billion in May, climbing £9.1 billion compared to the same month last year. Some of that increase traces back to inflationary pressures linked to the ongoing Middle East conflict, which has kept energy costs elevated and rippled through government procurement budgets.

On the revenue side, receipts did grow, rising £3.7 billion to £94.8 billion. But that improvement was nowhere near enough to offset the spending surge.

The cumulative picture looks even more uncomfortable. Combined borrowing for April and May, the first two months of the current financial year, reached £46.3 billion. That’s £7.7 billion above projections. April alone came in at £24.3 billion, also above the OBR’s estimates, meaning the government has been running hotter than expected from the very start of the fiscal year.

Public sector net debt now stands at 95.1% of GDP. In English: for every pound the UK economy produces in a year, the government owes roughly 95 pence.

The debt interest trap

A significant portion of UK government debt is linked to inflation through index-linked gilts. When inflation runs hot, the cost of servicing that debt rises automatically. The Middle East conflict has exacerbated this dynamic by keeping energy prices elevated, feeding into broader inflation metrics that directly increase the government’s debt servicing bill.

The 95.1% debt-to-GDP ratio also deserves historical context. The UK hadn’t seen debt levels this high relative to economic output since the post-World War II era, when the country was rebuilding from physical destruction.

What this means for investors

The immediate concern for markets centers on gilt yields. When the government borrows more than expected, it needs to issue more bonds, and that increased supply tends to push yields higher. Rising gilt yields have a cascading effect: they increase borrowing costs for businesses, push up mortgage rates, and generally tighten financial conditions across the economy.

For the Bank of England, the data creates an awkward dilemma. Persistent inflation, partly driven by external factors like the Middle East conflict, argues for keeping interest rates elevated. But higher rates also increase the government’s debt servicing costs on new issuance, potentially worsening the fiscal position that’s already under strain.

With nearly half a fiscal year’s worth of projected borrowing consumed in just two months, the UK government faces mounting pressure to either cut spending or find new revenue sources.