KiwiRail's about to get railroaded over its locomotive plans.

The Green Party's organised a protest outside the company's Auckland headquarters this morning to protest plans that could see KiwiRail ditch its aging electric locomotives in favour of new diesel ones.

MP Julie-Anne Genter says taxpayers deserve clean transport choices and to ditch the electric locomotives is a short-sighted decision.

"I would argue that if we want to have a smart, low carbon transport system that's going to be economically efficient and help New Zealand well into the future, we need to be looking at investing in that infrastructure."