Global bond sell-off intensifies as US-Iran tensions stoke inflation fears

The global government bond sell‑off intensified on Wednesday, pushing the yield on 10‑year UK gilts to just under 5.3%, the highest level since mid‑2008, and raising borrowing costs for Britain as Finance Minister John Healey prepares his first budget. The rally in yields follows renewed US‑Iran hostilities that have lifted oil prices to around $95 a barrel, stoking inflation fears and prompting expectations of further central‑bank rate hikes worldwide. Analysts warn that the surge in gilt yields could erase almost half of the fiscal headroom the government created in its spring forecast, tightening the space for Healey to meet fiscal rules without resorting to tax hikes or spending cuts.

Higher borrowing costs are compounded by broader market turmoil, with Asian equities tumbling—Japan’s Nikkei down 2.85%, China’s CSI 300 slipping 1.4% and South Korea’s Kospi falling 3.3%—as investors react to the Middle‑East conflict and to US policy moves aimed at stabilising the yen and buying back Treasury bonds, which have so far failed to curb rising yields. Deutsche Bank economists estimate that the £26 billion margin for fiscal manoeuvre could shrink to under £14 billion by the October 28 budget, forcing the UK government to confront a stark trade‑off between fiscal consolidation and the need to fund heightened defence spending.

The pressure on the UK’s finances reflects a wider global squeeze as governments confront tighter bond markets amid geopolitical risk and inflationary pressures. Commentators such as IG’s chief market analyst Chris Beauchamp note that while many nations feel bond‑market strain, the UK is especially vulnerable given its large debt load and ambitious economic reform agenda championed by figures like Andy Burnham. The outcome of Healey’s budget will hinge on how the Treasury balances the reduced fiscal cushion against the imperative to contain inflation, support defence, and maintain market confidence in a volatile international environment.

⚡ Effects Interpreter