UK bond markets brace for potential turmoil ahead of Reeves’s Budget amid rising yields and political uncertainties

A leading City of London investor has issued a stark warning to Chancellor Rachel Reeves ahead of her upcoming Budget on November 26, highlighting the precarious fiscal and market environment she faces. David Zahn, head of European fixed income at Franklin Templeton, which manages $1.69 trillion in assets, cautioned that bond markets could react harshly if the Budget fails to instil confidence, potentially forcing the government into a second fiscal statement.

Zahn emphasised that the principal risk lies in market disappointment rather than celebration. He noted that if bond investors respond negatively, yields on UK government bonds could spike sharply, resulting in borrowing costs that become unsustainable for the government. According to Zahn, yields on 10- or 30-year gilts reaching levels around 6% would trigger a “death spiral,” where rising borrowing costs fuel further market unease and exacerbate fiscal pressures. Currently, 30-year gilt yields stand at about 5.35%, down from a peak near 5.75% earlier this year, while 10-year yields hover around 4.53%.

The core of the concern is Labour’s expected reluctance or inability to implement substantial spending cuts, which Zahn argues narrows options for reducing borrowing and easing gilt yields. The investor pointed out that if the Budget does not address major tax reforms, markets may remain unimpressed. He described the situation as “fixing” the problem insufficiently, noting that no spending cuts are anticipated, which undermines investor confidence.

Recent reports indicate that Chancellor Reeves has abandoned plans to raise income tax, a move Zahn believes markets would have viewed more positively as a sign of fiscal tightening. Instead, she is expected to freeze tax thresholds, a fiscal mechanism expected to raise around £10 billion annually by pushing more taxpayers into higher brackets through “fiscal drag.” Reeves may also introduce smaller tax increases across other areas to boost revenues. However, these measures could fall short in reassuring bond investors seeking clear signs of fiscal discipline.

Labour’s promise to reduce government debt within five years also faces pressure. Initial projections suggested only a slim fiscal headroom of £10 billion to meet this target, but this buffer may have eroded further due to downward revisions in the UK’s long-term productivity forecasts. Zahn suggested that markets would prefer to see at least £20 billion of fiscal headroom to feel comfortable with the Budget. He also hinted at the likelihood of additional tax hikes in the following years, suggesting the possibility this Budget might not be a one-off event for such measures.

Beyond purely economic factors, political dynamics could add to market volatility. Analysts at ING warned that any post-Budget rise in borrowing costs may reflect political uncertainties rather than fundamental economic reasons. James Smith, developed markets economist at ING, highlighted concerns over Labour’s falling poll ratings and pressure on Prime Minister Keir Starmer, which might fuel speculation about leadership challenges. Markets could anticipate that a new prime minister might appoint a more left-leaning chancellor, potentially abandoning current fiscal rules and permitting greater borrowing.

The shadow of the 2022 mini-budget crisis under former Prime Minister Liz Truss continues to influence investor sentiment, as noted by Michael Brown, global investment strategist at Franklin Templeton Institute. That episode, with its abrupt fiscal missteps leading to soaring gilt yields and market chaos, still looms large as a cautionary tale. Brown remarked, “The markets don’t forget that either,” underscoring the perceived risk that the UK fiscal position could once again falter.

Recent developments in the gilt market mirror this tension. UK government bond yields have climbed to levels not seen since the late 1990s and early 2000s. In October, 10-year gilt yields hit 4.89%, their highest since 2008, while 30-year yields reached 5.39%, their highest since 1998. This rise in yields contributed to expectations that the Bank of England might delay interest rate cuts due to inflationary pressures linked to increased government borrowing and spending. The Bank itself has recently slowed its reduction of gilt holdings to mitigate volatility, underscoring the fragility in these markets.

Despite this, Treasury Minister James Cartlidge has maintained that UK bond markets remain orderly amid rising borrowing costs. Nonetheless, the pressure on Reeves to deliver a credible fiscal plan that satisfies both markets and political commitments is palpable. The intersection of high borrowing costs, subdued economic growth forecasts, and political uncertainties presents a difficult balancing act.

In summary, Rachel Reeves prepares to present a Budget under intense scrutiny, with major concerns over whether it can successfully reassure bond markets and maintain fiscal credibility. The possibility that bond market reactions might compel a secondary budget cannot be discounted. Investors, analysts, and policymakers alike will be watching closely to see if the government strikes a credible path that can stabilise borrowing costs and restore confidence, or if the UK risks another period of fiscal turbulence.