Investors are demanding the highest returns on British government debt in over two decades, with the yield on 30-year gilts touching 5.79% this week — a level not seen since 1998. The surge reflects a confluence of global and domestic pressures that are testing the credibility of the UK's fiscal framework and the stability of Keir Starmer's government.
The yield on the 10-year gilt also spiked, briefly hitting 5.11%, close to an 18-year high, before settling around 4.93%. Bond yields rise when prices fall, indicating that investors perceive UK debt as riskier and require a larger premium to hold it over the long term.
Why yields are climbing
The primary driver is the expectation that the Bank of England will keep interest rates elevated for longer to combat persistent inflation. Surging energy prices, exacerbated by the ongoing conflict in Iran, have heightened fears that inflation will remain "sticky" above the 2% target. The UK, heavily reliant on energy imports, is particularly vulnerable. Richard Carter, head of fixed interest research at Quilter Cheviot, told Euronews that "the UK is expected to be the worst hit developed economy by events in the Middle East due to its reliance on energy imports, so the longer energy prices remain elevated, the deeper the pain the country is likely to experience."
Beyond geopolitics, domestic political uncertainty is compounding the sell-off. After Labour's victory in 2024, Starmer's government introduced strict fiscal rules — including a "Stability Rule" requiring a budget surplus by 2029/30 and an "Investment Rule" targeting public sector net financial liabilities — alongside a fiscal lock that mandates independent OBR assessments for major tax or spending changes. Yet bond markets remain sceptical, fearing that political necessity will override fiscal discipline.
Starmer faces mounting pressure from the left of his party, with calls to loosen fiscal conservatism to address crises in the NHS and local government. The disastrous appointment of Peter Mandelson as ambassador to Washington, and revelations of his past ties to Jeffrey Epstein, have further damaged the administration's credibility.
Local elections as a referendum on fiscal credibility
The local elections on Thursday, covering 136 authorities and over 5,000 council seats, have become a high-stakes verdict on Labour's viability. Analysts project Labour could lose over 1,000 seats, a result that would intensify internal calls to replace Starmer with candidates like Angela Rayner or Andy Burnham, both seen as more willing to increase borrowing and spending.
Dan Coatsworth, head of markets at AJ Bell, warned that "any major setback to Labour will fuel calls for Keir Starmer to be replaced as prime minister and if that happens, bond markets will want to know who is taking over." He added that "the obvious challengers, Angela Rayner and Andy Burnham, are seen as candidates who might push for greater government borrowing and spending, which could take gilt yields even higher."
Richard Carter echoed this sentiment: "The uncertain UK political backdrop has played a role ahead of the local elections with gilt investors concerned about a Labour Party lurch to the left should Keir Starmer either be replaced or have little choice but to appease his backbenchers."
The implications extend beyond the UK. Higher gilt yields increase borrowing costs for the government, potentially squeezing public spending and complicating fiscal policy. They also affect European bond markets, as investors reassess risk across the continent. The situation echoes broader debates about fiscal discipline in the EU, where countries like Italy and France face similar pressures. For context, see our analysis of Macron's revived push for Eurobonds amid the energy crisis.
As the local election results unfold, bond markets will remain on edge. The outcome could determine not just the immediate trajectory of gilt yields, but the long-term stability of British borrowing costs and the political future of the Starmer government.
