(Peter Stevenson/The Washington Post)

The House Intelligence Committee’s probe of alleged Russian meddling in the 2016 elections, including potential ties between the Trump team and the Kremlin, is effectively on hold, after its chairman said the panel would not interview more witnesses until two intelligence chiefs return to Capitol Hill for a still-unscheduled private briefing.

Committee Chairman Devin Nunes’s declaration Tuesday that “until [FBI Director James B.] Comey comes forward, it’s hard for us to move forward with interviews and depositions” comes as an indefinite stop order on a roster of expected interviews and testimony, from top Trump campaign surrogates to top intelligence and law enforcement officials serving during the election and transition period.

Late last week, Nunes (R-Calif.) canceled an open hearing scheduled for Tuesday that would have featured testimony from former director of national intelligence James R. Clapper Jr., former CIA director John Brennan, and former acting attorney general Sally Yates. He did so, he said, “in order to make time available” for Comey and National Security Agency Director Mike Rogers to brief the panel on “additional information” that came up during an open hearing with the same spy chiefs last Monday.

But the closed-door meeting was never scheduled.

According to several Democrats on the committee, Nunes also canceled two regular panel meetings this week, without giving them a reason. Such “hot spots” meetings, which normally take place on Mondays and Thursdays according to Democrats on the panel, are not solely dedicated to the Russia investigation, but cover any matters that come under the committee’s purview.

“Effectively what has happened is the committee’s oversight, oversight of our national intelligence apparatus, has come to a halt because of this particular issue,” said committee member Jim Himes (D-Conn.).

“In my three years here, I’ve never seen us have a full week without a hearing,” committee member Eric Swalwell (D-Calif.) said. “We’ve made no progress since last Monday’s open hearing, and that is intentional.”

A spokesman for Nunes said the “hot spots” meetings were never scheduled and will resume next week.

The effective freeze in the committee’s Russia investigation comes as Democrats are calling for Nunes, who was part of Trump’s transition team, to recuse himself from the probe. Their demand was inspired by Nunes’s announcement that he went to the White House last week to meet a secret source who provided him with information suggesting identities of either President Trump or his transition team surrogates may have been improperly revealed after being picked up in surveillance of foreign targets. The next day, Nunes briefed the news media, then the president and then the news media again before taking that information to his colleagues on the Intelligence Committee, enraging Democrats, who have accused him of coordinating with the White House to draw attention away from the Russia investigation.

Nunes has since apologized for what he said was a “judgment call” but not admitted to any wrongdoing and refused calls for him to step down.

But although Democrats want Nunes to step aside on the Russia investigation, they are raising a far more urgent cry for him to schedule the outstanding hearings — and quickly, so they can get the House investigation back on track.

“Schedule them both, and I think we can move forward,” committee member Jackie Speier (D-Calif.) said, referring to both the expected closed briefing with Comey and Rogers, and the canceled open hearing with Clapper, Brennan and Yates. “You see the unraveling of this committee happening overnight for no good reason. We have a responsibility to do this investigation.”

(Jayne Orenstein,Ashleigh Joplin/The Washington Post)

A committee aide said Democrats on the panel offered to schedule both hearings next week but have not heard back from Nunes. The aide said that the holdup for Nunes appears to be that he did not want Yates, in particular, to testify.

The Trump administration tried to block Yates from testifying this month, according to a Washington Post report. The administration denied Tuesday that it had tried to block Yates’s testimony.

Nunes told reporters Tuesday that he intended to reschedule Yates, Clapper and Brennan for an open hearing “as soon as we can get the questions answered from the FBI director.”

“That would be a logical first step,” Nunes added.

But he did not say when he expected Comey to return to the committee or whether he believed the FBI director could answer all his questions in one more closed-door meeting.

Nunes and Rep. Adam B. Schiff (Calif.), the ranking Democrat on the committee, are also waiting on information from the FBI, NSA and CIA in response to a letter they sent the three agency directors this month, asking for a full list of names of U.S. persons whose identities had been exposed after popping up in surveillance reports directed at other targets. Nunes, who has refused to reveal his source or the full substance of what he has seen, told reporters that the information he viewed at the White House suggesting that even the president’s identity may have been revealed would be part of those documents.

Nunes said Tuesday that he expected the NSA to turn over the information about such “unmasked” names to the committee by Wednesday or Thursday of this week. He did not say when the committee would receive similar information from the CIA and FBI, which also have legal procedures to reveal incidentally collected names internally when doing so is important to understand a surveillance report’s intelligence value.