FERC has ordered Mountain Valley Pipeline LLC (MVP) to stop nearly all construction along the entire 300-mile route just days after a federal court stayed key authorizations for the project.

In a letter on Tuesday, the Federal Energy Regulatory Commission said all construction must cease immediately except for restoration and stabilization of the right-of-way and work areas that the company deems necessary to protect the environment and wildlife. MVP had already voluntarily suspended construction activities in August where work could have imperiled federally listed species or risked modifying their habitats along some portions of the project.

During the broader suspension, FERC said it would work with the U.S. Fish and Wildlife Service (USFWS) to evaluate the impacts of allowing construction to continue outside the areas where work has been suspended by the company.

MVP stopped some work after environmental groups challenged the projects Biological Opinion (BO) and Incidental Take Statement (ITS). Last week, the U.S. Court of Appeals for the Fourth Circuit stayed those authorizations, which are needed for the project to move forward. The USFWS is expected to revise and reissue the BO and ITS by January.

MVP, which would move 2 Bcf/d of Appalachian shale gas to Southeast markets, has been targeting a mid-2020 in-service date. It is more than 85% complete, but the project has faced repeated regulatory and legal delays. FERC also ordered all construction to temporarily stop last year after the Fourth Circuit vacated authorizations to build across federal lands.