On danger that Trump could fire Mueller, Congress needs to speak up, 'don’t wait for crisis': Leading Democrat Firing Mueller would lead to a "constitutional crisis," Rep. Adam Schiff said.

The top Democrat on the House Intelligence Committee said Sunday that congressional members need to “speak out” now about the importance of the special counsel’s Russia investigation, before there’s a “constitutional crisis.”

Rep. Adam Schiff of California was responding to a question from ABC News Chief Anchor George Stephanopoulos on "This Week" Sunday. “What would happen if the president” fired special counsel Robert Mueller? Stephanopoulos asked.

Schiff said, “I would hope that it would prompt all Democrats and Republicans in the House to pass an independent-counsel law and reinstate Bob Mueller. This would undoubtedly result in a constitutional crisis, and I think Democrats and Republicans need to speak out about this right now.”

“Members need to speak out now," the California Democrat continued. "Don't wait for the crisis, but I would hope that that would be the result -- that we would affirm our system of checks and balances and appoint an independent counsel."

The White House has repeatedly said there are no plans to fire Mueller, but President Donald Trump tweeted Saturday night that the investigation “should have never been started.”

The president’s latest tweets criticizing the Russia investigation came after Friday’s firing of former Deputy FBI Director Andrew McCabe, leading to speculation that the president may act to remove the special counsel.

Asked whether McCabe’s firing was justified, Schiff said, "You know, his firing may be justified. There's no way for us to know at this point, but even though it may have been justified, it can also be tainted."

Stephanopoulos asked Schiff about the president's tweets and a statement by Trump attorney John Dowd to The Daily Beast on Saturday suggesting that the Justice Department official who appointed Mueller end the probe.

“I pray that Acting Attorney General Rosenstein will bring an end to alleged Russia Collusion investigation," Dowd said, calling the probe "manufactured."

Schiff said, "I think, George, you just pointed to the single most important development of the week and that is at the same time it's revealed that the special counsel is looking at business records of the Trump Organization," referring to a New York Times report Thursday that Mueller’s team has subpoenaed Russia-related records from president's business, the Trump Organization. ABC News has confirmed this report with multiple sources familiar with the matter but has not seen the subpoenas.

"I've always thought the money laundering issue was the most serious," Schiff said. "You have the president through his lawyer trying to shut down the Mueller investigation and speaking out against special counsel."

Stephanopoulos also asked about this week's announcement by the Republican majority on the House Intelligence Committee that they are ending their probe of Russia's meddling in the 2016 election after concluding there was no collusion by the Trump campaign.

"I know you dispute that," Stephanopoulos said to Schiff. "But will a report by the Democrats [on the committee] be able to demonstrate that collusion did, in fact, take place?"

"Well, it certainly would be able to show the facts supporting the issue of collusion and the secret meetings, all the lies about the secret meetings, and putting them in their important context, the timing of these secret meetings," the California representative said. "But there's still a lot of investigative work to find the remaining pieces of the puzzle and the most significant part of the Republicans shutting us down is they're preventing us from doing so."