The top Republican and Democrat on the House Intelligence Committee escalated their feud on Friday, with GOP Chairman Devin Nunes announcing that he wished to cancel a public hearing next week and Ranking Member Adam Schiff charging Nunes with bad faith and attempting to choke off an independent hearing.

In a press conference at the Capitol Friday morning, Nunes announced that Paul Manafort, Donald Trump’s former campaign manager, had offered through his attorney to testify before the committee as it investigates Russian interference in the presidential election. But Nunes also announced he wanted to cancel an open hearing scheduled for next week, with former Acting Attorney General Sally Yates, former CIA Director John Brennan, and former Director of National Intelligence James Clapper, until the committee had a chance to have a closed hearing with FBI Director James Comey and NSA Director Mike Rogers. He said his decision did not have anything to do with new documents he received this week.

About an hour later, Schiff held his own press conference, calling Nunes’s announcement a “serious mistake” and accusing him of bowing to White House pressure.

“I think that there must have been a very strong pushback from the White House about the nature of Monday’s hearing,” he said. “It’s hard to come to any other conclusion about why an agreed-upon meeting was canceled.”

While Schiff did not say Democrats would pull out of the investigation, he called for an independent commission and said anyone watching this week’s drama would have “very legitimate concerns” about whether the House investigation would be credible.

The dueling press conferences cap an astonishing week in the Russia investigation. On Monday, the committee held hearings with Rogers and Comey, in which Comey confirmed for the first time that the FBI is investigating potential collusion between Trump campaign officials and Russia to interfere in the election.

On Wednesday, Nunes made a strange announcement in which he said he had obtained documents about surveillance of Trump team officials. But Nunes’s revelation was extremely vague: First, he repeatedly said he did not yet have all the facts. Second, he said that all surveillance appeared to have been lawful, and involved Trump transition team officials whose information was “incidentally collected” in the course of communication with foreign nationals under legal surveillance. He said he was concerned about “unmasking” of U.S. persons—citizens’ names and information are generally redacted, or masked, unless somehow relevant. But Nunes could not or would not say who or why it appeared “inappropriate,” in his words.

Even stranger was Nunes’s handling of this revelation, which came from a source he would not reveal. Despite having only partial information, he did not inform Schiff or other members of the committee. Instead, he briefed Speaker Paul Ryan, made a public announcement, and then went to the White House to brief Trump. Although Nunes continued to say that Trump’s claims of having been “wiretapped” by President Obama were baseless, the cloak-and-dagger handling, along with Nunes’s close ties to the president, elicited accusations that he was trying to throw Trump a political lifeline. Whether or not that was true, the president took it that way. He said on Wednesday that he felt “somewhat” vindicated, and Press Secretary Sean Spicer again used the v-word on Thursday.

Schiff was furious. He blasted Nunes in a press conference, accusing him of “act[ing] as a White House surrogate.” Then Schiff went on MNSBC’s Meet the Press Daily, where he announced that there was evidence that was “more than circumstantial” of collusion between Russia and the Trump administration.

On Thursday, Nunes gestured toward making nice, apologizing to the committee for going to Trump before he spoke with Schiff. But in a contradictory move, he later told reporters he did not regret handling the situation in the way he did. Nunes also seemed to back away from some of his comments on Wednesday, with a spokesman telling ABC News the chairman did not know for sure whether Trump or any of his associates were even on the communications he had cited.

Later Thursday, he went on the Fox News show of close Trump confidant Sean Hannity, where he explained that he had felt “a duty and obligation” to brief the president “because as you know he’s taking a lot of heat in the news media. The answer seems to validates concerns that Nunes is acting more as a Trump ally then as the head of an independent congressional investigation.

Meanwhile, Schiff built on his “evidence” comments in an interview with CNN. “I do think that it's appropriate to say that it's the kind of evidence that you would submit to a grand jury at the beginning of an investigation,” the former federal prosecutor said. “It's not the kind of evidence that you take to a trial jury when you're trying to prove something beyond a reasonable doubt.”

Finally, Fox News reported that GOP investigators in Congress “expect a potential ‘smoking gun’ establishing that the Obama administration spied on the Trump transition team, and possibly the president-elect himself.”

That brings things to Friday, and the latest public bout between Schiff and Nunes. Nunes has put himself in an apparently untenable situation, in which he feels compelled to act as both investigator and ally of the president. By coming forth with new information, he has opened up an enormous set of questions, but because the information is incomplete and, presumably, classified, he cannot and will not put any of those questions to rest, as his increasingly quizzical exchanges with reporters show. Meanwhile, the sniping between the chair and ranking member casts doubt on whether the House investigation can proceed, or whether it can be perceived as credible. It’s hard to imagine that the committee could become any more dysfunctional—but given the week’s pattern, just wait a few hours.