Equinox and SoulCycle are facing backlash after a report that the brands' chairman is holding a fundraiser for President Donald Trump.

Stephen Ross, the chairman of the company that owns both brands, is scheduled to host a Trump fundraiser charging $100,000 per ticket this week, The Washington Post reported.

Now Equinox members and SoulCycle visitors are threatening to cut ties with the trendy fitness brands.

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Equinox and SoulCycle are facing backlash over the brands' chairman's ties to President Donald Trump.

Stephen Ross, a real-estate developer and investor, is planning to host a fundraiser for Trump's reelection on Friday in his New York home in the Hamptons, with tickets costing $100,000, The Washington Post reported.

Ross is the founder and chairman of the real-estate company Related Cos. and the owner of the Miami Dolphins.

Ross' fundraiser has sparked boycott threats from Equinox members and SoulCycle fans. The Related Cos. acquired Equinox in 2005, and Ross sits on the board of directors; SoulCycle is owned by Equinox.

"This Friday the Soul Cycle and Equinox Fitness chairman is throwing a fundraising lunch for Donald Trump's 2020 presidential campaign," #GrabYourWallet founder Shannon Coulter tweeted Wednesday.

"Tickets are $100,000 each. Adding to the list," she added, referring to #GrabYourWallet's influential list of brands for anti-Trump people to boycott.

Read more: People are saying the Tucker Carlson boycotts are a betrayal of free speech. They're wrong.

Others voiced similar concerns on social media, with many people threatening to cancel their Equinox memberships.

—Ari (Yet Another Stallion) Fitz (@itsarifitz) August 7, 2019

Equinox's Instagram page has also been flooded with negative comments about the fundraiser.

"Is it true that the owner of Equinox is a Trump supporter? Say it ain't so!!! I will have to quit," one comment reads.

SoulCycle is also seeing backlash online.

SoulCycle and Equinox released similar statements on Wednesday afternoon, calling Ross a "passive investor" and saying the brands are unconnected with the fundraiser.

"We want to let you know that Equinox and SoulCycle have nothing to do with the event and do not support it," Equinox tweeted. "As is consistent with our policies, no company profits are used to fund politicians."

In addition to Equinox and SoulCycle, Related Cos. has made major investments in the dessert chain Milk Bar, the celebrity chef David Chang's Momofuku restaurant empire, the fast-casual chain &pizza, and the gym brand Blink Fitness.

Ross has long had ties to the GOP, holding a fundraiser for Jeb Bush in 2016.

He is apparently friendly with Trump, speaking with the president during the controversy over NFL players kneeling during the national anthem to protest police brutality, the New York Daily News reported. Ross, apparently influenced by Trump, decided that the Miami Dolphins would require players to stand.

"I like Donald [Trump]. I don't support everything that he says," Ross told the Daily News in March 2018.

"Overall, I think he was trying to make a point, and his message became what kneeling was all about. From that standpoint, that is the way the public is interpreting it. So I think that's really incumbent upon us to adopt that."