Director liability expanded: 'tax due' now covers penalty, interest and other payable sums under the Income-tax Act. The amendment clarifies that the expression 'tax due' for purposes of directors' liability in respect of an unrecoverable liability of a private company includes penalty, interest and any other sum payable under the Income-tax Act, without altering the pre-existing joint and several liability framework or the directors' burden to prove absence of gross neglect, misfeasance or breach of duty.