Australian borrowers have entered the “toughest part of the economic cycle” National Australia Bank boss Andrew Irvine says after the nation’s biggest business lender reported arrears had accelerated at their quickest pace in five years.

Mr Irvine disclosed that arrears had jumped to 1.39 per cent of all lending – worth roughly $10 billion – as of September 30, revealing his first full-year result as chief executive to shareholders on Thursday. This is the highest point since 2020, and up 26 basis points from 1.13 per cent this time last year.