The Rail and Maritime Union is organising a public meeting in Whangarei over the end of rail freight north of Kauri.
KiwiRail is ending its contract with the Marusumi chipmill at Portland, and the daily log train from the mid-north that supplies the mill will stop after August.
At present hundreds of trucks a day carry logs from the Far North to Whangarei - because there was no rail connection between the existing railway line and Northport.
The union's Northland organiser Albie Barr said Kiwirail's chief executive had been invited to explain why that was happening when Northland people did not want more log trucks on their roads.
He said Northland MP Winston Peters and the union's leaders have also been invited to speak along with other local MP's.
Mr Barr said he understood Kiwirail needed new wagons for the Northland line but could not afford them, but it had failed to consult its workers about the cuts to rail freight - let alone the public.
The meeting is set for the evening of 4 April at Whangarei's Forum North.
Save Our Rail Northland said connecting the Northland lines to the forestry port would cost $250 million, but it was a pittance compared to the amount the government spent on roads.
Spokesman Alan Preston said New Zealand spends $21 million a day importing oil, while a railway line that could take logs all the way to the port would make the entire network viable.
Mr Preston said there was a lot of unease in the Northland community over the threat to rail.