National Australia Bank directors informally met this week to discuss the major lender’s chief executive, Andrew Irvine, backing him to continue in the role but urging him to improve his presentation amid disquiet from investors about his management style and drinking at client events.

Irvine is expected to return from overseas shortly and is scheduled to speak at the Australian Banking Association’s conference in Sydney next week, his first public appearance since reports about investor unease were published in The Australian Financial Review. Irvine is the chairman of the banking lobby’s 16-member council, a position that rotates between members.