UK borrowing costs jump amid uncertainty over PM's futureGovernment borrowing costs jumped on Tuesday amid uncertainty over the future of Prime Minister Sir Keir Starmer. The effective interest rate on borrowing over 10 years rose to 5.13%, near levels last seen during the 2008 global financial crisis. Financial markets have been on edge due to fears that the Iran war will push up inflation and lead to interest rate hikes, but the possibility of a change of leadership in the UK and perceived risk of looser public spending has unsettled some investors. Some 80 Labour MPs have called for Sir Keir to resign following poor election results last week, but the PM has told his cabinet to "get on with governing". "The Labour Party has a process for challenging a leader and that has not been triggered," he told his senior colleagues, before some voiced support for him to continue in post. While all governments have seen borrowing costs rise since the Iran war, the UK has experienced elevated ra..