DES MOINES, Iowa (AP) — Iowa landowners are asking a judge to stop construction on the four-state Dakota Access oil pipeline until their constitutional challenges are heard.

A dozen landowners asked a state court in documents filed Tuesday in Des Moines to immediately hear the motion and keep the Texas-based company from digging a trench across their land.

Their attorney, Bill Hanigan, says the Iowa Utilities Board misinterpreted a 2006 state law that bans agricultural land from being taken for private projects via eminent domain.

He says the board’s finding that the pipeline benefits Iowa residents and makes them safer is “cover to facilitate the naked transfer of private property from Iowa’s politically disfavored farmers to favored big oil companies.”

Dakota Access said it is continuing construction on schedule. Work already has begun in North Dakota, South Dakota and Illinois.