White House could take months to decide on invoking executive privilege

— -- The White House could be months away from deciding whether President Donald Trump should invoke executive privilege to block Attorney General Jeff Sessions, or others, from telling lawmakers about private conversations with the commander-in-chief.

That decision process is "in its infancy," one source familiar with the procedures told ABC News.

The issue came to a head on Tuesday when Sessions publicly appeared before the Senate Intelligence Committee as part of its widening probe into Russia's alleged interference in last year's presidential election and the subsequent firing of James Comey as FBI director.

"It would be inappropriate for me to answer and reveal private conversations with the president when he has not had a full opportunity to review the questions and to make a decision on whether or not to approve such an answer," Sessions told lawmakers. "I am protecting the right of the president to exert [executive privilege], should he choose it."

Democrats pounced, accusing Sessions of "stonewalling" and "obstructing" the Senate committee’s investigation. Sen. Ron Wyden, D-Oregon, even said the attorney general, by refusing to invoke executive privilege, had "acknowledged there is no legal basis for this stonewalling."

In fact, though, Sessions was following longstanding Executive Branch and Justice Department policies -- the same policies most recently reinforced by Barack Obama's administration.

Two months after Barack Obama’s inauguration, the White House’s top lawyer, Greg Craig, issued a memorandum to the attorney general and other department heads laying out what he said were "procedures ... designed to ensure that this Administration acts responsibly and consistently with respect to White House confidentiality interests, with due regard for the responsibility and prerogatives of Congress."

The memorandum said the White House counsel’s office and the relevant department should first "work with appropriate congressional representatives to determine whether a mutually satisfactory accommodation is available."

It goes on to say that if those efforts "are unsuccessful," the White House counsel and the attorney general should then "consult" with each other "to determine whether to recommend that the President invoke the privilege."

Craig's memo called this a "longstanding policy" set forth in another memorandum sent to department heads nearly 35 years earlier by then-President Ronald Reagan.

"Historically, good faith negotiations between Congress and the Executive Branch have minimized the need for invoking executive privilege, and this tradition of accommodation should continue as the primary means of resolving conflicts between the Branches," Reagan wrote in his Nov. 4, 1982, memorandum.

Reagan's memo outlines the method department heads can use to decline answering questions without officially invoking executive privilege.

If, after extensive consultations with the White House counsel and "careful review," the impasse reaches a point where the president needs to decide whether to officially invoke executive privilege, then the department head -- in this case Sessions -- "shall request the Congressional body" suspend its request for information "to protect the privilege pending a Presidential decision."

In this case, the "request itself does not constitute a claim of privilege."

During his testimony on Tuesday, Sessions made clear that he was "following the historic policies of the Department of Justice."

"I am not stonewalling," he insisted. "You don't walk in to any hearing or committee meeting and reveal confidential communications with the president of the United States, who is entitled to receive confidential communications and your best judgment about a host of issues."

This consultation process is only just beginning, one source said, although new developments or unforeseen circumstances could accelerate the process. A Congressional subpoena, in particular, could force the administration to make a decision even sooner, the source said.

On Tuesday, Sen. Dianne Feinstein, D-California, specifically wanted to know if Sessions ever discussed Comey’s handling of the Russia investigation or Comey’s subsequent firing with President Trump. Sen. Martin Heinrich, D-New Mexico, wanted to know if President Trump ever expressed frustration to Sessions over the attorney general’s decision to recuse himself from the any campaign-related investigations.

Sessions declined to answer those questions and Democrats made clear they objected.

"You took an oath," Heinrich told Sessions. "You raised your right hand here today and you said that you would solemnly tell the truth, the whole truth and nothing but the truth, and now you're ... impeding this investigation."

Warner agreed and made a reference to Director of National Intelligence Dan Coats and National Security Agency Director Mike Rogers, who last week refused to publicly answer questions over whether President Trump urged them to help stop the FBI’s Russia-related probe.

"In the past several weeks, we've seen a concerning pattern of administration officials refusing to answer public, unclassified questions about allegations about the president," he said.

While they acknowledge they didn’t have a “legal basis” for declining to answer, they said they felt it would be “inappropriate” to discuss private conversation with the president in a public setting.

On Monday, Rogers met with the Senate Intelligence Committee behind closed doors, and the committee’s chairman, Sen. Richard Burr, R-North Carolina, said lawmakers’ questions were “thoroughly answered.”

Coats is privately meeting with the committee this afternoon.

An ABC News request for comment from Greg Craig, the White House counsel to President Obama, was not immediately returned.