The British pound is experiencing a notable downturn, heading for its worst weekly performance in 18 months, as concerns mount over a potential leadership challenge to Keir Starmer from Andy Burnham, the Mayor of Greater Manchester. This political uncertainty has led to significant fluctuations in the currency, with traders reacting to the implications of a possible shift in leadership within the Labour Party.
Political Turmoil and Currency Response
As speculation grows regarding Starmer’s leadership, the pound has depreciated by approximately three cents, or 2.2%, this week, settling at $1.332 on Friday—a five-week low. This decline marks the steepest drop against the US dollar since November 2024, coinciding with the aftermath of Donald Trump’s election victory. The political landscape in Westminster has become increasingly volatile, particularly following Burnham’s announcement that he plans to run for the parliamentary seat in Makerfield.
“The pound is under pressure this morning after a significant drop yesterday, triggered by Burnham’s entry into the leadership discussion,” noted Kathleen Brooks, research director at XTB. She remarked that Burnham is perceived as the least market-friendly candidate, especially when compared to the recent resignation of Wes Streeting, which did not elicit a similar market reaction.
Rising Borrowing Costs and Economic Implications
In addition to the currency fluctuations, UK government borrowing costs have surged amid a broader sell-off of sovereign debt. The yield on UK 10-year bonds has risen to 5.18%, the highest since 2008, surpassing the 18-year peak recorded earlier this week. Meanwhile, yields on 30-year bonds have also increased sharply, reaching 5.85%.

This sell-off reflects market apprehension regarding a potential Burnham premiership, which investors fear could lead to a relaxation of the UK’s fiscal discipline and an increase in public spending. Burnham’s previous comments on the UK’s fiscal situation, describing it as being “in hock to the bond markets,” have left investors wary, although he has since tempered his rhetoric in subsequent interviews.
Neil Wilson, an investor strategist at Saxo UK, commented that markets are likely to react unfavourably to the idea of a left-leaning Prime Minister whose fiscal views are already well established. “The bond market is likely to impose fiscal discipline, but there could be turbulence before that happens,” he cautioned, underscoring the fragility of the UK’s fiscal position amid ongoing geopolitical tensions.
The Path to Leadership and Its Challenges
While Burnham’s popularity is evident—he holds the only net positive approval rating among major UK politicians according to YouGov—he still faces significant hurdles before he can challenge Starmer. He must first secure a byelection in Makerfield, a constituency where the Reform UK party performed well in recent local elections and where the Green party is also expected to contest.
The current sitting MP, Josh Simons, is stepping down to facilitate Burnham’s return to Westminster, although he holds a slim majority of just over 5,000 votes. Analysts predict that the uncertainty surrounding Burnham’s potential leadership will continue to fuel volatility in gilt markets as speculation regarding fiscal policy changes persists.
The Importance of Stability
Bill Diviney, head of macro research at ABN Amro, highlighted that Burnham’s public appeal could be a double-edged sword. “With the right support, particularly if Rachel Reeves retains her role as Chancellor, it could signal continuity and reassure markets,” he stated, referencing the importance of maintaining fiscal stability.

The ongoing discourse around Labour’s leadership is not merely an internal party matter; it carries broader implications for the UK economy and financial markets.
Why it Matters
The unfolding political drama poses significant implications for both the economy and investors’ confidence in the UK’s fiscal outlook. With the pound’s value in jeopardy and government borrowing costs rising, the situation underscores the urgency for clarity and stability within the Labour Party. Should Burnham’s leadership bid materialise, it will undoubtedly shape not only the political landscape but also the economic trajectory of the UK in the months to come.