Union representatives from the country's ports meet in Wellington on Monday to discuss Fonterra's partial withdrawral from the ports of Timaru and Taranaki.
The dairy co-operative announced earlier this month it would move more of its goods by rail to larger ports, reducing the volume of its exports from Timaru by 80% and Taranaki by 65%.
In Timaru, port workers have been told that five full time jobs will go as a result.
Maritime Union general secretary Trevor Hanson says the Government should explain why it is allowing the taxpayer-funded rail network to threaten the future of the regional ports.
Union representatives are also meeting the general manager of Fonterra's supply chain strategy, Nigel Jones, to discuss fears about the impact the move will have on the country's export industry.