Labour's transport spokesperson Sue Moroney says the imminent closure of part of the Northland railway line is a vote of no-confidence in the region.
Kiwirail denies the line is closing, but documents show it needs money spent on bridges and new wagons, and the log trains that run on it will stop in September.
The Marusumi chip mill said that was because Kiwirail has refused to renew the freight contract when it expires in August.
Ms Moroney said it was a short-sighted decision that will clutter Northland roads with more trucks, and make them more dangerous.
The government was not investing in rail but looking at increasing the size of trucks allowed on Northland highways - while at the same time cutting funding for local roads.
That was a recipe for disaster, she said.
Kiwirail has in recent years tried to find more customers for the northernmost stretch of the line, to make it more economic, but without success.