It seems like Republican presidential frontrunner Donald Trump has become too big of a threat even to his own party.

An operation has been set up to oust the controversial business tycoon from the race to the White House, according to a report from The Wall Street Journal.

This so-called "guerrilla campaign" against Trump is reportedly led by Liz Mair, the former online communications director of the Republican National Committee.

Mair recently founded Trump Card LLC, an enterprise with only one goal: launch political attacks against Trump.

"In the absence of our efforts, Trump is exceedingly unlikely to implode or be forced out of the race," according to the Trump Card memo, as quoted by The Wall Street Journal.

Trump Card LLC is worried that if Trump ends up becoming the Republican party's nominee for the 2016 presidential race, the Democratic frontrunner, Hillary Clinton, will breeze her way through the White House.

"The stark reality is that unless something dramatic and unconventional is done, Trump will be the Republican nominee and Hillary Clinton will become president," the memo read.

Mair refused to name the individuals funding the campaign to discredit Trump.

"It's loosely organised and highly confidential," she said. "I certainly know donors who are very happy that their fingerprints will be kept off things."

Nevertheless, Trump's rivals in the Republican presidential race seem to be on board. Ohio Gov. John Kasich, for instance, is already airing a series of ads targeting the controversial businessman.

Former Florida Gov. Jeb Bush, meanwhile, has also been launching verbal attacks against Trump over the past days.

In response to the attacks being orchestrated against him, Trump threatened to sue people behind the efforts to destroy and discredit him. He also belittled Mair by saying she "worked for Scott Walker and lost her job—who can blame her?"