Trump has allowed the release of the memo, which Democrats say is a crude attempt to undermine Mueller’s Trump-Russia investigation. Republicans on Friday released a controversial memo that alleges an abuse of power by the FBI in its investigation into Russian meddling in the 2016 election, after Donald Trump declassified the document and accused top officials of bias.

The House intelligence committee chairman, Devin Nunes, published the memo minutes after the president’s approval, despite a warning from the Department of Justice that it would be a “reckless” act. Democrats have portrayed the memo as a crude attempt to undermine the credibility of the Robert Mueller investigation into possible collusion between the Kremlin and members of the Trump campaign.

The four-page memo, released with a letter from the White House, alleges that the FBI omitted key information when it applied for a wiretap on an adviser of Trump’s campaign. The findings “raise concerns with the legitimacy and legality of certain DOJ and FBI interactions” with the court that approves surveillance requests, the memo says. It also claims they “represent a troubling breakdown of legal processes established to protect the American people from abuses”.

The memo’s central claim is that the FBI omitted context in its application to surveil the Trump adviser, Carter Page. The document notes that the FBI used material compiled by former British spy Christopher Steele, whose work was funded by Democrats, and who the memo says was “desperate that Donald Trump not get elected and was passionate about him not being president”.

The memo also claims that the FBI “terminated” Steele as a source because he spoke with the media, and that texts between an FBI agent and FBI attorney “demonstrated a clear bias against Trump”. The agent was removed from the investigation in December.

The release follows a week of partisan rancor over the memo in Washington, and Democrats and former law enforcement officials swiftly condemned the declassification, joined by at least one senior Republican senator, John McCain.

“The latest attacks on the FBI and Department of Justice serve no American interests – no party’s, no president’s, only Putin’s,” McCain said on Friday.

In a rare statement, the FBI Agents Association mounted a defense of the rank-and-file agents it represents. “The men and women of the FBI put their lives on the line every day,” the association said, “because of their dedication to tour country and the constitution.”

“FBI special agents have not, and will not, allow partisan politics to distract us from our solemn commitment to our mission,” it added.

For weeks, Democrats have said the memo cherry-picks classified intelligence to cast Rod Rosenstein, the deputy attorney general, as a villain in an FBI plot to surveil Page.