The by-election battle for Mt Roskill is well and truly underway, with Labour promising light rail to the Auckland suburb if it wins next year's election.
But is it about transport or politics?
Labour's associate transport spokesman Phil Twyford says it's the former.
"It's very funny that the Prime Minister comes on your show and wants to rubbish it - it's his policy. We're just bringing it forward. It's in the plan."
Watch the full interview with Phil Twyford.