A lawsuit by House Democrats seeking President Donald Trump’s tax returns was put on hold while a U.S. appeals court decides whether judges have the power to resolve disputes between Congress and the White House.

U.S. District Judge Trevor McFadden in Washington issued a stay on the tax case Friday — the second in two months — to wait for a full federal appeals court to decide if Congress can compel testimony from former White House counsel Don McGahn. A three-judge appellate panel ruled 2-1 in February that the court lacked jurisdiction to resolve disputes between the executive and legislative branches.

The review by the full appellate court could signal the panel’s decision will be thrown out, according to Jennifer Rodgers, a former federal prosecutor and a lecturer at Columbia Law School. That would bolster the case for lawmakers who want to use their subpoena power and the authority granted in the tax code to obtain six years of Trump’s personal and business tax returns.

“The subpoena-enforcement issue is unsettled for now,” McFadden said in the order. “And piecemeal litigation would be an inefficient use of resources.”