Wall Street's Democratic donors are warning they won't back Sen. Elizabeth Warren if she wins the party's nomination, and might even support President Donald Trump, according to CNBC.

"You're in a box because you're a Democrat and you're thinking, 'I want to help the party, but she's going to hurt me, so I'm going to help President Trump,'" a senior private equity executive told CNBC.

Warren plans to break up the big banks, crack down on private equity, and regulate executive pay if she becomes president.

View Markets Insider's homepage for more stories.

Wall Street's Democratic donors are warning they won't back Sen. Elizabeth Warren if she wins the party's nomination, and might even support President Donald Trump, according to CNBC.

"You're in a box because you're a Democrat and you're thinking, 'I want to help the party, but she's going to hurt me, so I'm going to help President Trump,'" a senior private equity executive told CNBC.

Warren, a vocal critic of big banks, plans to crack down on the financial industry if she becomes president. In response to a CNBC tweet promoting its story, she wrote "wealthy donors don't get to buy this process" and vowed she wouldn't "back down."

Twitter/Elizabeth Warren

The Massachusetts senator's presidential plans include breaking up the big banks, dividing commercial and investment banking, and forcing private equity firms to shoulder debts and pension costs tied to businesses they buy.

She also intends to get rid of sweetheart tax rates, protect workers when their employers go broke, penalize bankers for failed risky investments, and reverse the Trump administration's deregulation of the financial industry.

"To raise wages, help small businesses, and spur economic growth, we need to shut down the Wall Street giveaways and rein in the financial industry so it stops sucking money out of the rest of the economy," Warren wrote in a Medium blog post in July.

Warren topped the latest CNN/Des Moines Register/Medicacom poll with 22% of support, outstripping Vice-President Joe Biden's 20% share. Three-quarters of those surveyed held a favorable view of her, and 32% of her supporters were "extremely enthusiastic," compared with 22% for Biden.

Her recent momentum means the stance of withholding support and potentially switching to Trump "is becoming widely shared" among wealthy Democratic donors and fundraisers in business circles, CNBC reported.

Bank executives and hedge fund managers "will not support her," a big-bank executive told CNBC, adding that Warren's policies would be worse for the industry than President Barack Obama's changes. "It would be like shutting down their industry."

Wall Street executives are saying Warren "has got to be stopped," Jim Cramer said on CNBC's Mad Money this month. "I'm Elizabeth Warren, and I approve this message," the senator tweeted in response to the video.

Twitter/Elizabeth Warren

The prospect of Warren revealing Trump's tax cut to be a gift to the wealthy has also turned Wall Street off Warren.

"I think if she can show that the tax code of 2017 was basically nonsense and only helped corporations, Wall Street would not like the public thinking about that," a hedge fund executive told CNBC.

NOW WATCH: Octopuses are officially the weirdest animals on Earth