President Trump on Monday ordered the declassification of several key documents related to the FBI investigation of Russian actions during the 2016 presidential election, including 21 pages of an application for a renewed surveillance warrant against former campaign aide Carter Page, and text messages from disgraced FBI figures Peter Strzok and Lisa Page.

Rep. Adam Schiff (Calif.), the top Democrat on the House Intelligence Committee, said Trump's "selective release of materials he believes are helpful to his defense team and thinks will advance a false narrative" is a "clear abuse of power," and based on his conversations with federal law enforcement officials, the FBI and Justice Department see the release of these unredacted documents as "a red line that must not be crossed as they may compromise sources and methods."

David Kris, former chief of the Justice Department's national security division and founder of the Culper Partners consulting firm, said Mr. Trump's action was "especially unprecedented" because he was overruling subordinates who had provided a redacted version of the surveillance application to Congress and because the order pertained to a continuing investigation of which Mr. Trump is a subject.

Democrats on Monday contended that the declassification order was another salvo in a partisan battle being waged to protect Mr. Trump and discredit an investigation that has already resulted in guilty pleas or convictions of his former campaign chairman, his former national security adviser and several others involved in his campaign or his business.

"President Trump, in a clear abuse of power, has decided to intervene in a pending law enforcement investigation by ordering the selective release of materials he believes are helpful to his defense team and thinks will advance a false narrative," said Rep. Adam Schiff (D., Calif.), the top Democrat on the House Intelligence Committee.