More articles of impeachment could be recommended against U.S. President Trump, according to lawyers for the House Judiciary Committee.

A federal court filing spelled out the prospect for a second impeachment if more evidence of Trump's alleged crimes is uncovered in further investigations. The argument was made that Democrats still needed testimony from former White House counsel Don McGahn.

"If McGahn's testimony produces new evidence supporting the conclusion that President Trump committed impeachable offenses that are not covered by the Articles approved by the House, the Committee will proceed accordingly — including, if necessary, by considering whether to recommend new articles of impeachment," the lawyers said in a court filing to the D.C. Circut Court of Appeals.

The president has instructed McGahn, who left the administration last year, not to comply with a congressional subpoena to testify.

The House panel has been trying to get the federal appeals court to compel McGahn to testify, and they have implied that if the testimony is damning enough, it could lead to further charges against the president.

The House of Representatives impeached President Trump last week for abuse of power and obstruction of Congress.

The Justice Department has argued that U.S. courts should stay out of the investigations and shouldn't give the House the information it's asking for.

The White House has claimed that former and current officials have absolute immunity from congressional subpoenas and cannot be compelled to testify. The decision by the appeals court could have a significant impact on the Senate's impeachment trial and any further investigation.