The largest trade union federation in the United States on Friday joined a growing chorus of business and political organizations calling for President Donald Trump's immediate removal from office following Wednesday's violent riot that he instigated.

"The deadly storming of the US Capitol by a mob looking to overturn the results of a free and fair election, encouraged and inspired by President Donald Trump, was one of the greatest attacks on our democracy in American history," the federation said in a statement.

"Trump is an affront to every union member, and a clear and present danger to our nation and our republic," the organization added. "He should resign or be removed from office at once, whether through impeachment or the 25th Amendment to the US Constitution."

The statement came as congressional Democrats moved ahead with efforts to remove Trump over the attack on the Capitol, even with President-elect Joe Biden set to take office on January 20.

The Wednesday assault saw a mob of angry Trump supporters storm the US Capitol shortly after Trump reiterated baseless election conspiracies to the crowd and told supporters "if you don't fight like hell, you're not going to have a country anymore."

The AFL-CIO also criticized the pliant response of law enforcement to the rioters, echoing statements from Biden and others that have seen the treatment as reflective of double standards in policing as compared with the response to anti-racism protests that broke out nationwide over the past summer.

Trump supporters clashed  with police and security forces as they stormed the US Capitol on January 6
Trump supporters clashed with police and security forces as they stormed the US Capitol on January 6 AFP / Joseph Prezioso

"The fact that trespassers were allowed to roam the halls of Congress without consequence is one of the latest examples of why we must tear down the systems and abiders of white supremacy," the AFL-CIO said of the demonstrators, some of whom brandished the flags of the pro-slavery Confederacy in the US Civil War.

"Hate and insurrection have no place in America," the group said.

The labor group's statement is among the toughest so far, joining the National Association of Manufacturing, which urged Vice President Mike Pence to consider invoking the 25th amendment, and Ben & Jerry's ice cream, which said Wednesday's display "was not a protest -- it was a riot to uphold white supremacy."

Numerous other groups have also condemned Wednesday's events, but avoided calling out Trump by name, or stopped short of recommending a specific action, such as impeachment.

A statement Thursday from the Business Roundtable said the attack stemmed from "elected officials' perpetuation of the fiction of a fraudulent 2020 presidential election" and called for nation to "unite around President-elect Biden and Vice President-elect Harris."

On Friday, Barry Diller, chairman of tech holding firm IAC, dismissed talk of impeaching or invoking the 25th amendment as "silliness," adding that Trump would be irrelevant after he leaves office in 12 days.

"It's 12 days to go, hold your breath," Diller told CNBC. "Let him go and let him be over."