Two Pennsylvania judges have dealt a setback to efforts by power companies to build a major new Pennsylvania-Virginia mega-transmission line, saying the line is unnecessary and that alternatives should have been considered.

The $1.3 billion project proposed by Allegheny Energy and Dominion Energy was initially approved in Virginia last month, but it has run into fierce opposition in western Pennsylvania.

In a recommendation last week, the administrative law judges for the Pennsylvania Public Utility Commission recommended that the agency should deny an application to build the power line.

The recommendation is not final. Allegheny Energy, which would build the portion of the line in Pennsylvania, will have a chance to respond before the utility commission considers the matter.

At the heart of the debate is a 2005 federal law which allows the federal government to override state regulators for power lines that are deemed to be critical to the nation’s electric power needs, and it grants them the use of eminent domain law to compel private owners to sell their property. The law is being contested by Pennsylvania’s utility commission.

The 500-kilovolt transmission line would run 240 miles from Washington County, Pa., across West Virginia to Loudoun County, Va., in an effort to supply more power to mid-Atlantic states.