Labour list MPs Anne Hartley and Dianne Yates plan to quit Parliament after the summer recess.
Ms Hartley was elected to the North Shore City Council on Saturday but Ms Yates failed to win a seat on the Hamilton City Council.
Both say they will stand down.
Ms Yates told Radio New Zealand that she would take up work with community groups.
The next two people on Labour's list are Louisa Wall, a former Silver Ferns netballer, and Manukau City councillor Su'a William Sio.
Mr Sio has been picked by some to replace Taito Phillip Field as Labour's candidate in Mangere.
Ms Hartley's departure also opens the position of Assistant Speaker.