Low oil prices and the high cost of extracting Canadian oil are casting new doubts on the Keystone XL pipeline as project developer TransCanada faces its final regulatory hurdle in Nebraska.

Keystone would snake from Canada’s tar sands through Montana, South Dakota and Nebraska, and then connect with existing pipelines in Kansas and Oklahoma to carry more than 800,000 barrels of crude oil a day to specialized refineries along the Texas Gulf Coast.

After nine years of protests, lawsuits and political wrangling that saw the Obama administration reject Keystone XL only to have President Donald Trump revive it, the economics of the project have worsened. Shippers have also found other ways to transport oil.

Project opponents say they’re not letting their guard down and will continue to protest.

Officials with Calgary-based TransCanada will try to persuade the Nebraska Public Service Commission to approve the pipeline during a series of hearings that start Monday. The company says it will decide whether to proceed with the pipeline in late November or early December.