Concerned at the complete lack of progress in designating a rail corridor from Onehunga to Auckland Airport and continuing back to Wiri, the CBT wrote to Mayor Len Brown suggesting Manukau City start to look into it.
Mayor Brown has responded, indicating that a Memorandum of Understanding is being prepared between KiwiRail, Manukau City, ARTA, ARC and Auckland Airport to do exactly that. The exercise will be led by ARTA.
Full response is here.