The Rail & Maritime Transport Union is accusing KiwiRail of preparing to out source more engineering and infrastructure work after announcing it will be cutting 181 jobs.
The union says managers and contracting companies have been telling its members there will be more contract work available soon.
Fulton Hogan recently bought new rail maintenance vehicles and is seeking rail workers on its website, due to what it calls significant company growth.
Fulton Hogan says it has no commitment from KiwiRail for more projects.
KiwiRail says it is scaling back maintenanceoperations so there will be no extra work to out source.
KiwiRail says if companies are advertising for rail personnel, they have done it off their own backs.