WASHINGTON – The furor over President Trump's abrupt firing of FBI Director James Comey grew Wednesday with the revelation that Comey had sought more resources for an investigation into possible coordination between the Trump campaign and the Russian government shortly before he was dismissed.

Republicans and Democrats alike expressed dismay Wednesday over Comey's firing the day before, which several said will frustrate bipartisan efforts to investigate Russian interference in the 2016 election and any possible ties between the Kremlin and Trump associates. Many Democrats called for a special prosecutor to take on the investigation.

Although several congressional officials, including Sen. Richard Durbin, D-Ill., confirmed that Comey had informed lawmakers of the request he made last week in a meeting with Deputy Attorney General Rod Rosenstein, the Justice Department denied those reports.

Spokeswoman Sarah Isgur Flores called the reports "totally false." Such a request for more funding or other resources for the Russia investigation are, she said, "did not happen."

But officials said Comey made his appeal to Rosenstein, who also wrote the Justice Department's memo that was used to justify the firing of Comey this week.

"I'm told that as soon as Rosenstein arrived, there was a request for additional resources for the investigation and that a few days afterwards, he was sacked," Durbin said. "I think the Comey operation was breathing down the neck of the Trump campaign and their operatives, and this was an effort to slow down the investigation."

The timing of Comey's request is not clear-cut evidence that his firing was related to the Russia investigation. But it is certain to fuel bipartisan criticism that Trump appeared to be meddling in an investigation that had the potential to damage his presidency.

"This really smacks of impropriety," said Sen. Jon Tester, D-Mont., who said he believes the president is "using Hillary and the server as an excuse to say, 'We're getting rid of this guy because he's getting too close to us.' "

Frustrated by resources

In his briefing with members of Congress, Comey said he had been frustrated with the amount of resources being dedicated to the Russia investigation, according to two of the officials. Until two weeks ago, when Rosenstein took over as deputy attorney general, the investigation was being overseen by Dana Boente, who is now the U.S. attorney for the Eastern District of Virginia.

Comey has said he was hoping that he would find a supportive boss in Rosenstein and, according to the officials, pressed for more resources so he could accelerate the investigation, which is also examining possible collusion between Trump associates and the Russian interference campaign.

To a president who puts a premium on loyalty, Comey represented a fiercely independent official who wielded incredible power. Comey made his career standing up to members of the George W. Bush administration on matters of surveillance. And his advisers have cast his handling of the investigation into Hillary Clinton's use of a private e-mail server as evidence that he was equally willing to criticize the Democratic nominee for president.

Several influential Republicans, including Sens. John McCain and Bob Corker, declined to say whether they accepted the reasons given for Comey's firing. However, Senate Majority Leader Mitch McConnell, R-Ky., dismissed concerns and rapped Democrats for complaining about the ouster of an FBI director they had "repeatedly and sharply criticized."

For now, a cloud remains over the FBI-led investigation, which by all accounts was managed closely by Comey, who spent much of his career as a federal prosecutor. "This was obviously the most important, most sensitive, most critical investigation that the FBI is currently conducting," Carrie Cordero, a former counselor to the assistant attorney general for national security, told a podcast. "So that means it is more likely than not that the director has been getting briefed probably every single day."

Comey's abrupt departure will knock the wind out of the sails of the investigation, at least temporarily, Cordero said.

Others echoed that a temporary slowdown in the probe was likely.

"It's undoubtedly going to cause some dislocation inside the FBI and to people in the National Security Division of Justice," said Barry Coburn, a former federal prosecutor. "They have to get reorganized to figure out who will be the point person in the FBI and who will make key investigative decisions. It raises very substantial concerns about the possibility that whoever takes over from Comey might stop, subvert, divert or otherwise impact the investigative activity that otherwise would have been taken."

'Wanting to send a warning shot'

Few professionals in the Justice Department said they believe that Comey's firing was tied to anything other than the displeasure of the White House at the Russia investigation.

"Everybody reads this as the White House wanting to send a warning shot across the bow of the Russia investigation and to slow it down," said Christopher H. Schroeder, a former assistant attorney general who headed the Office of Legal Policy. He now teaches at Duke University's law school.

Some career investigators may not take kindly to the political pressure, said Alex Whiting, a former federal prosecutor who teaches at Harvard Law School.

"If they feel like this was designed to push them back, they will be emboldened," Whiting said, and may confront Rosenstein, who has taken the reins of the Russia inquiry because Attorney General Jeff Sessions withdrew from involvement after it was disclosed that he met twice with Russia's ambassador last year.

Whiting said he believes Rosenstein "is very weakened" as a result of his role in Comey's "orchestrated firing," and will soon feel pressure from senior Justice Department officials to name a special counsel to take over the Russia influence investigation.

Whiting said many career Justice Department officials care deeply about its image and the perception that it remains free of political meddling. "Any time that there's a perception that the independence of the Justice Department may have been compromised by a political decision, that's very damaging to the institution," he said. "And it's a lasting damage."

The New York Times and McClatchy Washington Bureau contributed to this report.