Dropkick Murphys, the American Celtic punk band best known for their 2005 hit “I’m Shipping Up to Boston,” announced on Wednesday that they will no longer perform at any Punk in the Park shows after discovering that the festival’s organizer donated to the Trump campaign.

“Punk Rock and Donald Trump just don’t belong together. So, upon learning that Brew Ha Ha promotions contributed to the Trump campaign, we will not be participating in any more Punk in the Park shows,” the band stated in an Instagram video caption.

In the video, frontman Ken Casey told an audience: “The far right ain’t the new punk.”

The band had just recently performed in Denver but said it will not continue for any other Punk in the Park shows.

Cameron Collins, owner of Brew Ha Ha, the group that organized the festival, posted his own statement in response.

“We live in a two-party system, and unfortunately, you must decide based on a few key issues that matter to you. For me, those issues included the promise to end wars and avoid new international conflicts, lower taxes, and preventing government overreach,” Collins said.

He added that he hasn’t liked many of Trump’s recent “viewpoints, opinions, and policies thus far” and said the festival has not donated any of its proceeds to any political party and will not.

Federal Election Commission records show Collins made multiple small-dollar donations last year to the Trump National Committee, Never Surrender and WinRed. The Trump National Committee and Never Surrender use funds raised to support Trump. WinRed bills itself as “the only fundraising platform built exclusively for conservatives.”

Like most punk bands, Dropkick Murphys identify with the broader left-wing movement, and they haven’t been shy about their opposition to Trump.

In March, Casey called out a fan wearing a “Make America Great Again” shirt at a concert. Upon making a wager and verifying that the “MAGA” shirt was made in Nicaragua, Casey had the fan change into a “proudly made in America Dropkick Murphys shirt.”

“We don’t care if we lose fans, because when history’s said and done, we want it known that Dropkick Murphys stood with the people, we stood with the workers,” Casey said at the time.

Punk in the Park is scheduled to make numerous stops through the end of the year, including dates in California, Oregon and Arizona.