The controversial memo outlining alleged abuses of secret surveillance by the FBI and Justice Department "provides no credible basis" for President Trump to fire Deputy Attorney General Rod Rosenstein, said a top Democratic lawmaker in a letter sent to colleagues on Saturday even as the White House has said there are no plans to make any changes at the DOJ.

The memo in question, released Friday by the House Intelligence Committee after it was declassified by the White House, notes that Rosenstein signed off on one renewal of a federal court surveillance warrant against Trump campaign adviser Carter Page.

In his letter, Rep. Jerold Nadler, D-N.Y., said that had Rosenstein, whom Trump nominated to be the DOJ's Number 2, not signed the FISA application it could have appeared like a political move.

“The Deputy Attorney General could not have signed an application to renew surveillance on Carter Page if the government was unable to show that it had already gathered valuable evidence under existing orders and expected that collection to continue,” wrote Nadler, who is the top Democrat on the House Judiciary Committee. “Under these circumstances, any decision not to approve the renewal would have appeared to have been politically motivated.”

Since Attorney General Jeff Sessions recused himself from Russia-related investigations, Rosenstein was the DOJ official who appointed special counsel Robert Mueller to head the federal Russia inquiry after Trump fired FBI Director James Comey in May of last year. He alone has direct authority to fire Mueller, who is looking into Russian interference in the 2016 election and whether the Trump campaign colluded with the Kremlin.

Nadler warned that Rosenstein had become a "target for those attempting to interfere with that investigation."

"President Trump has refused to rule out using the Nunes Memo as pretext for dismissing the DAG. 'You figure that one out,' he said when asked about the Deputy Attorney General on Friday," Nadler noted.

However, multiple White House officials have since clarified that Trump has no intention of firing Rosenstein.

"I'm saying it on behalf of the White House, and that's that no changes are going to be made at the Department of Justice," White House deputy press secretary Raj Shah said during a CNN interview on Friday. "We fully expect Rod Rosenstein to continue on as the deputy attorney general."

Still, with the release of the memo, devised by staffers under House Intel Chairman Devin Nunes, R-Calif., and a recent report that said Trump asked Rosenstein about the direction Mueller’s investigation was heading and whether he was “on my team," Democrats are spooked about a possible attempt to get rid of Rosenstein, potentially as a ploy to eventually get rid of Mueller.

The memo also mentions that Rosenstein was someone who worked “closely” with former Associate Deputy Attorney General Bruce Ohr, who was demoted after it was revealed by House investigators that he met with Glenn Simpson, the co-founder of opposition research firm Fusion GPS. Fusion GPS then used funds from the Hillary Clinton campaign and the Democratic National Committee to hire Christopher Steele to compile the "Trump dossier" that makes salacious and unverified assertions about Trump's ties to Russia.

Top congressional Democrats warned Trump on Friday against using memo as a pretext to fire Rosenstein and therefore halt the Russia investigation, creating a “constitutional crisis.” While some key Republicans, including House Speaker Paul Ryan, R-Wis., who this week said the memo "does not impugn the Mueller investigation or the deputy attorney general," have said the memo doesn't impact the Mueller investigation, some rank-and-file members disagree. Trump appears to as well.

"This memo totally vindicates 'Trump' in probe. But the Russian Witch Hunt goes on and on," Trump tweeted Saturday morning.

The memo shows that Republicans “are now part and parcel to an organized effort to obstruct” Mueller’s investigation, Nadler declared in his letter.

Nadler is one of a few lawmakers, Democrat or Republican, who had access to and has seen the underlying documents that supported the so-called Nunes memo. Last week he sent a letter to the chairman of the judiciary panel, pressing for an urgent meeting with FBI Director Christopher Wray to discuss areas of concern the FBI has regarding a controversial memo that allegedly outlines surveillance violations by the U.S. government. Democrats and the FBI had warned against the release of the Nunes memo, arguing that some of the claims could be damaging and misconstrued without the proper context and documents.

Another sticking point on which Nadler harps in his letter, obtained by NBC News, is about the key assertion in the memo related to the process by which Foreign Intelligence Surveillance Act warrant applications were submitted for approval by a judge to spy on Page. The document claims the Justice Department and FBI officials used information from the "Trump dossier," authored by ex-British spy Christopher Steele, to renew a surveillance warrant against Page.

"If not for this misrepresentation to the court, the story goes, there never would have been a Russia investigation. This claim is deliberately misleading and deeply wrong on the law," Nadler said.

Nadler argued that Steele's Russia and organized crime expertise counted for more in the consideration of a FISA application than who paid for his work. The memo alleged that DOJ officials knew Steele had an anti-Trump bias but made no mention of that in their effort to renew FISA surveillance on Page.

Nadler also said the Nunes memo "does not provide a single shred of evidence that any aspect of the Steele dossier is false or inaccurate in any way."

The letter comes as Democrats have pressed Nunes to allow the release of their classified counter-memo by adding what they say are details omitted in the Nunes memo. While House Intel did approve the Democrats' memo to be released to the entire House, in a similar fashion to how the GOP memo was treated at first, the panel rejected a push to make it public. Nunes, however, did express openness to putting it up to a vote in the future in a Fox News interview on Friday.