Agencies that deal with struggling families say any increase in dairy prices will end up hurting those who already find it hard to afford the basics.
Dairy prices surged by 7.2% at Fonterra's latest fortnightly auction on Wednesday, the fifth consecutive increase and the highest level since the online auctions began in July 2008.
International dairy price rises are likely to lead to people in this country eventually paying more for milk and other dairy products.
Federation of Family Budgeting Services chief executive Raewyn Fox says many families can no longer afford to buy milk.
Auckland City Missioner Diane Robertson says her organisation spends $18,000 a year on fresh milk, but it is having to restrict who receives it because of the cost.
She says milk, vegetables and fruit, which children most need, are increasingly becoming luxury items.