UK Borrowing Costs Surge to 18-Year High Amid Inflation and Geopolitical Concerns

London – British government borrowing costs have reached their highest level since the 2008 financial crisis, fueled by concerns over persistent inflation, rising interest rates, and escalating geopolitical tensions, particularly the conflict in the Middle East. The yield on the benchmark 10-year gilt surpassed 5% on Friday, March 20, 2026, marking a significant increase in the cost of government debt.

Rising Borrowing Costs and Public Finances

Public sector borrowing reached £14.3 billion in February, a £2.2 billion increase compared to the same period last year, according to the Office for National Statistics (ONS). This figure exceeded both the OBR’s November projection of £7.4 billion and economists’ expectations of around £8.8 billion.

Despite the monthly surge, cumulative borrowing for the first eleven months of the financial year (up to March) totaled £125.9 billion, a £1.9 billion reduction from the OBR’s November forecast and a £11.9 billion decrease year-over-year.

Gilt Yields and Market Reaction

Yields on 10-year UK government bonds (gilts) surged above 4.9% on Friday, reaching an 18-year high. This represents a jump from 4.78% the previous day. Gilts are essentially loans made to the UK government, with investors receiving interest payments over a set period.

The ‘yield’ on a gilt reflects the return an investor earns. Rising yields indicate increased borrowing costs for the government, as investors demand a higher return to compensate for perceived risk.

Impact of the US-Iran Conflict and Energy Prices

The recent increase in borrowing costs is largely attributed to concerns surrounding the escalating conflict between the US and Iran. The energy price surge resulting from the conflict has raised fears about the state of the public finances. The potential for increased government spending to support households with rising energy bills further complicates the fiscal outlook.

Yields on the U.K.’s 10-year government bonds have jumped around 68 basis points in the 15 trading days since the conflict began, while the yield on the 2-year gilt has added about 97 basis points.

Implications for Fiscal Policy

Economists suggest that the unexpected rise in borrowing and higher debt costs may limit the government’s ability to provide substantial fiscal support packages, such as those seen in 2022, even if the conflict in the Middle East escalates. Ruth Gregory, deputy chief UK economist at Capital Economics, stated that there is limited scope for large-scale fiscal support.

Key Takeaways

• UK government borrowing costs have reached their highest level since the 2008 financial crisis.
• February borrowing hit £14.3 billion, exceeding expectations.
• The conflict between the US and Iran is a major driver of rising yields.
• Higher borrowing costs may constrain the government’s ability to provide fiscal support.