UK government borrowing costs rise to the highest levels seen in decades as investors respond to political uncertainty around Prime Minister Keir Starmer. Multiple reports say the benchmark gilt yields surge, with long-term yields reaching their highest points in nearly three decades and 30-year yields at the highest level this century, while the pound falls against the US dollar and stocks decline. Investors appear to link the market moves to concerns about potential changes in Labour leadership and what that could mean for future government borrowing. Reports also reference pressure within Starmer’s government, including calls from cabinet-level figures and MPs urging him to step down, alongside resignations of ministerial aides. Starmer is described as consulting colleagues before an upcoming cabinet meeting, while speculation includes a possible leadership challenge involving Manchester mayor Andy Burnham. Analysts quoted by the BBC attribute parts of the market reaction to fears a Burnham-led administration could lead to higher government borrowing. Overall, the sources depict borrowing-cost increases as driven primarily by political uncertainty rather than a single new fiscal measure, alongside the reported influence of higher oil prices.