Former Act party president Catherine Isaac has been confirmed as the number two on the party list.
In a joint press statement, party leader Don Brash and president Chris Simmons confirmed that all candidates would move one place up the list to fill the position vacated by the retiring John Boscawen.
Ms Isaac was widely tipped to be the mystery candidate, but needed to confirm her availability, depending on the health of her husband and head of the Business Roundtable Roger Kerr.
Dr Brash said Ms Isaac was highly respected and had the unanimous support of the party board.
She was the party president between 2001 and 2006, and is currently managing director of a communications consultancy.