The Road Transport Forum is warning that food costs could increase if additional road user charges go ahead in Auckland.
Auckland mayor Len Brown raised the suggestion of congestion charges at a council meeting on Thursday, in which he revealed how he saw the city developing under a 10-year plan.
Mr Brown says charging motorists to use busy roads could be one way the council could raise the extra $10 billion needed for its transport plans, and nothing is set in concrete yet.
But Road Transport Forum spokesperson Calven Bonney says the price of food and the cost of transporting it are directly linked.
Mr Bonney, who owns a freight company, says a congestion charge would force the transport industry to pass the cost on due to tight margins.
