GOP congressman demands Mueller firing: It's time 'to put up or shut up' Rep. Matt Gaetz recently traveled with President Trump aboard Air Force One.

 -- Florida congressman Matt Gaetz, a House conservative who has led the charge against the Russia investigation and calls for a second special counsel, said Friday morning he wants Robert Mueller fired — and wants more Republicans to join in his cause.

“Congress has an obligation to expose what I believe is a corrupt investigation and I call on my Republican colleagues to join me in firing Bob Mueller,” Gaetz, R-Fla. said in an interview with CNN’s Chris Cuomo this morning. “It’s time for Mueller to put up or shut up. If there’s evidence of collusion with Russia, let’s see it.”

Gaetz is among of a handful of congressional Republicans who have called for ending the Mueller probe into possible collusion between the Trump campaign and Russia in 2016.

President Donald Trump has not publicly indicated he's considering firing Mueller.

However, the White House has indicated it has not ruled it out as a possible move the president could make.

“There is no intention or plan to make any changes in regards to the special counsel,” White House Press Secretary Sarah Sanders said in October.

A dismissal of Mueller would technically have to be made by Deputy Attorney General Rod Rosenstein — who serves as acting attorney general in all matters related to the 2016 election. President Trump could direct Rosenstein to fire the special counsel.

Rosenstein, who appointed Muller to handle the investigation, offered a strong defense of the special counsel during his testimony before the House Judiciary Committee Wednesday.

“I think it would be very difficult... for anybody to find somebody better qualified for this job,” Rosenstein said. “Director Mueller has throughout his lifetime been a dedicated and respected and heroic public servant.”

Gaetz has had the president's ear — traveling aboard Air Force One last Friday on his way to a Pensacola, Fla., campaign rally. Gaetz, who was joined on board by Rep. Ron DeSantis, R-Fla., has spent weeks — including prior to that trip — pushing efforts to fire Mueller.

Gaetz has argued that the special counsel's team has been "infected" with "intractable bias" against Trump.

In a phone interview with ABC News earlier this week, Gaetz said during that flight, Trump encouraged his oversight of the Department of Justice.

"I did let him know that we had Mr. Rosenstein come before the Judiciary Committee this week," he recalled to ABC News on Tuesday, ahead of Rosenstein’s Wednesday testimony before the House Judiciary Committee. "He simply encouraged Mr. DeSantis and I in very broad terms to continue exercise our oversight functions."

When asked about Robert Mueller being a Republican, Gaetz said Trump's "movement is a very unique coalition, and there are a lot of Republicans that aren’t a member of it."

Gaetz has also led the charge in Congress pushing Attorney General Sessions to appoint another special counsel to probe Uranium One and the Obama Justice Department.

Democrats and a number of prominent Republicans in Congress have publicly advised the against firing Mueller — some even supporting proposed legislation to protect the special counsel and ensure the investigation is completed.