By Lars Mucklejohn The boss of challenger Cynergy Bank has said small firms are letting too much money languish in no-interest current accounts, as it launches a new offering that puts it in more direct competition with Britain’s major lenders. Chief executive Nick Fahy told City A.M. that small and medium-sized enterprises (SMEs) are increasingly struggling to afford loan repayments as inflation continues to bite and the Bank of England holds interest rates at a 15-year high. “A business that would have been able to take on a million pounds of lending just two or three years ago could probabl…