Workers from KiwiRail's Hillside workshops marched down Dunedin's main street on Tuesday in protest at Hillside's being denied the chance to build electric trains for Auckland.
They're angry that KiwiRail prohibited Hillside from submitting a tender for the first part of the $500 million contract.
A Rail and Maritime Transport Union organiser, Jim Kelly, who also works at Hillside, says he and his colleagues feel insulted by their employer's stance.
He says they're now asking KiwiRail to ensure that the tender documents require some of the subcontracting work to be completed in New Zealand.
The march by more than 100 workers and supporters along George St ended with a rally in the Octagon.
Mr Kelly says the Hillside workers feel betrayed, and will continue to petition the Government and Kiwirail to include them in the project.