Andy Burnham is facing a renewed test from Britain’s bond markets, with borrowing costs surging ahead of his first Budget and raising the prospect of a fresh political confrontation with investors.
The Prime Minister has sought to reassure the City that his government will act with “fiscal responsibility” after a sharp sell-off in government debt pushed the yield on 10-year gilts to 5.29 per cent — its highest level since 2008. ([theguardian.com](https://www.theguardian.com/business/2026/sep/02/burnham-tries-to-calm-bond-market-fears-as-sell-off-threatens-budget))
The rise threatens to reduce the room for manoeuvre available to Chancellor John Healey as he prepares the Budget for 28 October. Higher gilt yields increase the cost of servicing the national debt and could force the Treasury to scale back spending plans or find additional savings and tax revenues.
Burnham’s predicament has echoes of Liz Truss’s brief premiership. Her unfunded tax-cutting mini-Budget in September 2022 triggered a collapse in the gilt market, prompting emergency intervention by the Bank of England and ultimately contributing to her removal from office after 44 days.
The current turmoil is not being driven solely by British politics. Investors have been selling government bonds internationally amid renewed inflation fears, higher oil prices and concerns about deficits. But the episode has highlighted the narrow margin facing the new Prime Minister as he attempts to combine cost-of-living measures with promises of greater public investment.
Bond yields threaten to squeeze the first Budget
The Office for Budget Responsibility is expected to base its forecasts on market interest rates recorded around this period. That means the recent rise in yields could be reflected directly in the calculations underpinning the Budget.
Analysts have estimated that higher debt-servicing costs could wipe out as much as half of the £24 billion headroom built up under the fiscal rules of Burnham’s predecessor, Rachel Reeves. The loss would leave the Chancellor with considerably less capacity to fund new measures without breaching those rules. ([theguardian.com](https://www.theguardian.com/business/2026/sep/02/burnham-tries-to-calm-bond-market-fears-as-sell-off-threatens-budget))
Helen Miller, director of the Institute for Fiscal Studies, said debt interest now accounted for roughly one pound in every £12 spent by the Government, meaning relatively small movements in borrowing costs could have a significant effect on the public finances. ([theguardian.com](https://www.theguardian.com/business/2026/sep/02/burnham-tries-to-calm-bond-market-fears-as-sell-off-threatens-budget))
Healey has repeatedly described fiscal discipline as the “bedrock” of the Government’s approach. He is also expected to set out his plans for economic growth in a speech next week, as pressure builds for the Treasury to show investors how its spending commitments will be paid for.
Burnham used his first Prime Minister’s Questions to insist that the October Budget would “stick to the fiscal rules” while also helping to ease pressure on household finances. The pledge was interpreted as an attempt to calm markets after his expansive programme of public intervention and additional defence spending.
The Prime Minister has previously argued that Britain must move beyond being “in hock to the bond market”. Investors, however, retain the power to raise the Government’s financing costs by demanding higher returns for holding its debt — a constraint that could determine how much of Burnham’s economic agenda survives his first Budget.
