As Keir Starmer’s leadership totters, investors warn a Labour leadership contest ignoring public finances and market realpolitik could be disastrousA rise in borrowing costs and warnings to avoid a “Liz Truss moment”. As Keir Starmer faces a potential leadership challenge, the spectre of the bond market looms large.Amid febrile conditions in Westminster, the prospect of Britain switching prime ministers for a sixth time in seven years has fuelled a sharp sell-off in the market for UK government...