A recent poll on NZ military spending (sorry I lost the link ) showed that 39% wanted an increase 30 % felt it was ok and should stay the same and 29% wanted a reduction.Given a fair slice of the NZ population is opposed to military spending of any kind, Labour would be concerned about bleeding support to the Greens, who can be guaranteed to oppose the purchase. Not a huge factor, but one the government strategists will definitely consider.