Long-term UK borrowing costs have soared to the highest level in nearly three decades while the pound and stocks fell, as investors braced for a potential change of leadership, with cabinet ministers urging Keir Starmer to quit . Starmer is consulting colleagues before a crunch cabinet meeting on Tuesday morning that comes after ministerial aides quit and more than 70 MPs publicly called for him to go. With investors worried over chaos and potential changes to the fiscal rigour of Starmer’s government, the yield – effectively the interest rate – on 30-year government bonds jumped 11 basis points to 5.794%, the highest since May 1998. The benchmark 10-year yield on UK government bonds (known as gilts) also rose 11 basis points to 5.11%, just below the highest levels since 2008 it hit in March amid fears that the Iran war will stoke inflation. The pound dropped 0.5% to $1.354 and was 0.3% lower against the euro, at 86.8p a euro.…