The Labour party is currently grappling with significant internal strife, manifesting as a leadership challenge that has brought the relationships between its most senior figures into sharp focus. According to a former enforcer for Gordon Brown, Damian McBride, a tactic to deal with leadership challengers is to "push them over the edge," a strategy seemingly employed by Keir Starmer's closest allies against Health Secretary Wes Streeting. This move, intended to quell rebellion, backfired, as Streeting, far from being a "reluctant bather," embraced the opportunity to position himself as a future leader with the confidence and fervour of an Olympic diver. Labour MPs and aides generally agree that Streeting emerged stronger from the incident, with one aide humorously comparing the strategists' miscalculation to "an elephant picking a fight with a shark and choosing to do it in the middle of the ocean."

At the heart of this extraordinary briefing war are Prime Minister Keir Starmer, his chief of staff Morgan McSweeney, and Wes Streeting. Conventional wisdom once suggested Starmer was a vehicle for McSweeney’s political project to shift Labour away from the hard left, potentially paving the way for Streeting. However, many now believe Starmer and McSweeney are inseparable, their fates mutually assured, with Starmer consistently backing his chief of staff. Despite this, recent months have seen a rift develop, leading to questions about McSweeney's longevity in No 10. Ministers and MPs have increasingly blamed him for bad decisions, including the full-frontal attack on Streeting. While some senior strategists later argued the intention was to show Starmer's fighting spirit, it largely appeared as a "paranoid overreaction." Some even speculated the move might benefit Streeting, a theory dismissed by insiders who recall McSweeney's critical view of Streeting's capabilities and political alignment.

The internal political turmoil, however, extends beyond leadership ambitions and has critical implications for the UK's economic stability, particularly for Rachel Reeves's impending November 26 budget. Reeves has been meticulously preparing for a tough budget, potentially including manifesto-busting income tax rises, to create fiscal "headroom" and reassure investors. This strategy aims to eliminate the "moron risk premium" – an additional premium investors demand for holding UK government debt due to political instability, a term coined during the chaotic Liz Truss period. Reeves's efforts had shown promise, with 10-year gilt yields drifting down, signaling reduced borrowing costs, before the latest political disruptions.

However, the recent outbreak of Labour infighting threatens to undermine this delicate progress. The political briefing wars have already caused market jitters, with 10-year gilt yields moving negatively, demonstrating a shift in investor focus from the budget's fiscal details to the broader political risk. As Neil Shearing, chief economist at Capital Economics, noted, "It’s moved off budget to political risk," with markets now intently watching how the budget lands with the parliamentary Labour party and the stability of Starmer's and Reeves's positions. This renewed emphasis on political instability is particularly frustrating for the Treasury, as it jeopardizes the hard-won market confidence. The consensus is that the government "has shot itself in the foot" by instigating such public internal conflict just as critical economic decisions loom. The success of Reeves's budget, and indeed the easing of the UK's substantial interest bill and cost of living pressures, hinges precariously on retaining credibility with the markets, a credibility now under threat from internal party divisions.