WASHINGTON — President Trump on Friday blocked the release of a classified Democratic memo rebutting Republican claims that top federal law enforcement officials had abused their powers in spying on a former Trump campaign aide, a move that Democrats denounced as politically motivated hypocrisy.

Last week, the president moved quickly, over the objections of the Justice Department and the F.B.I., to declassify the contents of a rival Republican memo drafted by House Intelligence Committee staff members. He claimed, incorrectly, that the Republican memo had vindicated him in the special counsel investigation into Russian election interference.

But Donald F. McGahn II, the president’s lawyer, said in a letter to the committee on Friday night that the Democratic memo could not be released because it “contains numerous properly classified and especially sensitive passages.” He said the president would again consider making the memo public if the committee, which had approved its release on Monday, revised it to “mitigate the risks.”

Under the obscure rule invoked by the Intelligence Committee to initiate the document’s release, the committee could choose to make those changes, or could decide to seek a vote of the full House to try to override Mr. Trump’s decision.