A Texas pipeline company’s lawsuit seeking potentially hundreds of millions of dollars from Greenpeace was set to advance with opening statements Wednesday in a trial the environmental organization calls an effort to silence critics of the oil industry.

Jury selection took place earlier in the week and the estimated five-week trial now will get underway in Mandan, North Dakota.

The lawsuit stems from protests in 2016 and 2017 against the Dakota Access oil pipeline and its controversial Missouri River crossing upstream of the Standing Rock Sioux Tribe’s reservation. The tribe has long opposed the pipeline as a risk to its water supply. The pipeline was completed in 2017.