RICHMOND, Va. — A federal judge has certified a handful of lawsuits as class actions accusing two energy companies of cheating southwest Virginia residents out of tens of millions of dollars in royalty payments for natural gas drilled on their land.

The lead attorney for the landowners said Tuesday he will ask for a summary judgment in the case and a full financial accounting from the companies for the thousands of wells they drilled in Virginia’s coalfields region to capture the methane gas from coal seams.

“This is a body blow to the defendants,” said Don Barrett, an attorney for the landowners who filed the initial lawsuits. “It’s a wake-up call to them.”

U.S. District Judge James P. Jones, ruling from Abingdon, accepted the recommendations Monday of a magistrate judge who concluded in June that the lawsuits should move forward as class actions.

CONSOL Energy Inc., the Pittsburgh-area parent of CNX Gas Co. who is bankrolling Tea Party candidate Ken Cuccinelli in his campaign to succeed Virginia governor Bob McDonnell, said in a statement it disagreed with the finding and was weighing its options. EQT Production Co. said it would appeal a portion of Jones’ ruling.