Some Republican donors seem to have had enough of Donald Trump's controversy-plagued White House bid and apparently pooled their resources to attack the real estate tycoon turned presidential candidate in a series of new television ads.

The contributors have links to the campaigns of several of Trump's GOP rivals, including former Florida Gov. Jeb Bush and Florida Sen. Marco Rubio, and have formed a group dubbed "Trump Card" to launch a "guerrilla" effort to defeat their party's current front-runner, Fox News noted.

According to The Wall Street Journal, the group is currently in the process of collecting funds to finance a media blitz attacking the former "Apprentice" star. It is apparently run by Liz Mair, a former communications official for the Republican National Committee (RNC).

Mair, who also used to work for Scott Walker before the Wisconsin governor dropped out of the 2016 presidential race, noted in a statement that Trump represented a threat to Republicans' chances of taking back the White House next year, according to an internal memo published by The Wall Street Journal.

"In the absence of our efforts, Trump is exceedingly unlikely to implode or be forced out of the race," she said. "The stark reality is that unless something dramatic and unconventional is done, Trump will be the Republican nominee and Hillary Clinton will become president."

Trump, for his part, has long contended that he is not receiving fair treatment from the RNC's establishment, which he suspects favors some of the more "traditional" candidates to win the GOP nomination. The 69-year-old businessman has refused to rule out an independent bid for the White House, should Republicans fail to make him their candidate, Fox News recalled.

The billionaire candidate seemed to reiterate that threat when he was asked about efforts to undermine him in a Sunday interview on ABC's "This Week."

"We'll see what happens," he hinted. "I have to be treated fairly. ... If I'm treated fairly, I'm fine."