Prime Minister Andy Burnham returned to Westminster facing soaring UK borrowing costs after a global bond sell-off pushed the 10-year gilt yield to 5.21 per cent, its highest since 2008, and the 30-year yield to 5.9 per cent, a peak since 1998. The spike complicates Chancellor John Healey's first Budget on October 28, with economists warning tax rises or spending cuts of roughly £10bn annually may be needed to restore fiscal headroom, which has shrunk from nearly £24bn to about £13bn.

The sell-off was fueled by Middle East tensions driving oil above $92 a barrel and European gas prices to 2023 highs. Modupe Adegbembo at Jefferies noted energy costs directly erode fiscal headroom, while Paul Diggle at Aberdeen highlighted UK "specific vulnerabilities" including a large deficit, weak growth, and energy exposure. Rob Wood at Pantheon Macroeconomics said the government must rebuild credibility with the Office for Budget Responsibility.

Downing Street insisted fiscal discipline remains the "bedrock of economic stability." Healey, at the G20 in the US, pledged tight fiscal control but has delayed defence spending decisions, including the 3 per cent of GDP interim target en route to a NATO goal of 3.5 per cent by 2035.