All meetings of the House Russia investigators were canceled this week shortly before the top Democrat, Rep. Adam Schiff, said Nunes must recuse himself in order for the investigation to continue.
Schiff also said Tuesday that he wants Republicans to agree to reschedule a pair of hearings that had been set for today -- including one where former acting Attorney General Sally Yates was expected to testify about communications between former Trump National Security Adviser Michael Flynn and Russian ambassador to the US Sergey Kislyak -- before agreeing to move forward with their investigation.
"We certainly welcome the director coming back at any time, but not as a substitute for the open hearing that he agreed to," Schiff told reporters Tuesday.
Nunes, however, told CNN Tuesday morning he was "moving forward" with the investigation and said he won't recuse himself.
"It moves forward just like it was before," Nunes told reporters.
It's a monumental shift from where House investigators planned to be Tuesday, interrogating a trio of former Obama administration officials in a public hearing. But last week's hearing -- the first and so far only public hearing of the House Russia investigation -- sparked a wildfire of partisan fighting after Comey confirmed he is investigating possible coordination between President Donald Trump's campaign aides and Russian officials.
The ensuing days saw Nunes brief Trump privately on new information of potential surveillance of Trump's aides before telling Democrats on the investigation. Nunes then apologized to Democrats, but the following day he canceled Tuesday's public hearing, saying he wanted to hear from Comey and National Security Agency Director Mike Rogers in private, prompting outrage from Democrats.
Nunes said Tuesday he formally invited Comey to testify again
, though he did not specify any details on timing.
A Republican House Intelligence Committee source defended the decision to try and move the Comey and Rogers hearing behind closed doors, saying Democrats are trying to kill the investigation.
"We just had 100 questions where Director Comey said that he couldn't answer in that setting, so you think the next step this week would be then 'OK, we'll come down and answer the questions in the closed session,'" the source said. "But from what I understand, we were not able to agree to have that done."
Asked to weigh in on calls for Nunes to recuse himself, the Republican source responded, "That's horses---."
The news Monday that Nunes met his source on White House grounds sparked the latest round of partisan fighting, which has left investigators unable to continue right now.
White House press secretary Sean Spicer dismissed accusations that the White House was being evasive on the specifics of Nunes' visit but refused to provide details on who signed the California Republican into White House grounds, as would be required protocol.
The White House on Tuesday also rejected allegations that it sought to prevent Yates from testifying
the House committee's investigation.
"The White House has taken no action to prevent Sally Yates from testifying and the Department of Justice, specifically told her that it would not stop her and to suggest otherwise is completely irresponsible," deputy press secretary Sarah Sanders said in a statement to CNN.
The statement came after The Washington Post reported
that the Trump administration sought to block Yates' testimony before Congress.
Even before Monday's stunning split, Democrats and Republicans said they were having a hard time agreeing on how to move forward in their investigation, unable to agree on which key witnesses to bring in. That split was punctuated by announcements from three key figures at the center of the FBI investigation -- former Trump campaign chairman Paul Manafort, former Trump adviser Roger Stone and former Trump foreign policy aide Carter Page -- that they would gladly testify before House investigators.
In private, Republicans have accused Democrats of "grandstanding" -- using Nunes trips to the White House as a means to kill an investigation that they say is unlikely to turn up any smoking guns of collusion between the Trump campaign and Russian intelligence. Democrats, meanwhile, have accused Nunes of attempting to "suicide bomb" his own investigation because they are convinced the evidence of collusion is there.
In a highly symbolic move Monday, after Nunes canceled a planned committee meeting, House Intelligence Republicans and Democrats still met in the same, classified briefing space in the Capitol where they typically meet but they gathered separately, plotting their own game plans.
Democrats believe Nunes is too close to the White House to lead a thorough investigation into Russia -- including ties between the Trump camp and Russian officials -- an assertion firmly rejected by the GOP.
"I don't think he can just recuse himself and still chair the committee," Rep. Jackie Speier, a Democrat on the panel, told CNN's Chris Cuomo Tuesday on "New Day." "I think that the writing is on the wall. It might make a good spy novel. It doesn't make a good investigation."
Comey and Rogers opted not to brief the panel amid the furor within the committee over how to proceed with its investigation.
The full committee typically meets at least twice a week and it's uncertain if those meetings will be rescheduled.
This story has been updated to reflect breaking news.