Rosenstein, who took office on April 26, is likely to be pressed about his involvement in the decision to fire Comey - an act carried out on May 9.
"The question is not if that move happens, but only when", said White House press secretary Sean Spicer.
"My understanding is the date for that hearing was just set", Spicer said.
He said he had not spoken to the White House counsel, Don McGahn, about the matter. I mean where oftentimes they give us opinions that we don't see a case there and so you ought to stop investing resources in it.
They say they also hope Comey's testimony will answer questions that have arisen since Comey's sudden firing by President Donald Trump. He made no attempt to correct his misleading testimony until the Washington Post revealed that, in fact, he had at least two meetings with the Russian ambassador during the 2016 presidential campaign.
In 1974, during the Watergate scandal, the U.S. Supreme Court ruled in U.S. v. Nixon that executive privilege can only be invoked in certain circumstances, such as when a president is trying to protect national security.More news: Raiders members share reactions, predictions on NBA Finals
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Mitch Sollenberger, a political science professor at University of Michigan-Dearborn, agreed, pointing out that courts would balance the public's interests with the president's need for secrecy. Any claim of protecting privilege could be undermined by Trump's tweets about his conversations.
Appearing on ABC's Good Morning America, White House adviser Kellyanne Conway trashed former Federal Bureau of Investigation director James Comey ahead of his Senate testimony saying morale at the agency he oversaw plummeted during his tenure.
Former FBI director James B. Comey appears before the Senate Judiciary Committee in Washington on May 3. But Trump himself has repeatedly said that the Russian Federation probe was on his mind when he removed Comey.
Specifically, according to sources familiar with the matter, at no point in the weeks and months before Comey's termination did Deputy Attorney General Rosenstein or Attorney General Sessions tell Comey they were uneasy about his leadership or upset over what Rosenstein later called Comey's "mistaken" decision to announce the results of the FBI investigation into Hillary Clinton's private email server a year ago. "That makes it very hard for him to now claim the right to secrecy", said Rozell.
Comey, ousted last month amid a federal investigation into connections between Russian Federation and the Trump campaign, is set to testify before Congress next week in a highly anticipated hearing that could shed new light on his private conversations with the president in the weeks before the firing.
The President has written about three separate conversations he had with Comey about whether he was under investigation, he further elaborated on those conversations in a televised interview with NBC, and he tweeted about them. The New York Times and Reuters consider the question, while Harvard law professor Noah Feldman writes about the issue in a column for Bloomberg. Arguably, Trump has himself breached that confidentiality.