• Jamie Dimon warned that higher UK bank taxes could affect plans for his London headquarters.
• The bank announced plans for the 3-million-square-foot, multibillion-dollar building in the fall.
• Ken Griffin has said he's reconsidering a Midtown office expansion amid a tax spat with Mamdani.

London's skyline might not get the JPMorgan treatment.

JPMorgan CEO Jamie Dimon said that increasing taxes on banks in the UK could thwart his plan for a new, multibillion-dollar London headquarters — the latest financial CEO to link major office investments to tax fights.

When asked in an interview with Bloomberg whether JPMorgan would reconsider plans for a new London office amid calls for UK Prime Minister Keir Starmer to resign, Dimon said political instability alone wouldn't alter the bank's plans — though that could change if the UK became "hostile" to banks.

"I've always objected to the fact — we didn't damage the UK in any way — we paid probably $10 billion back in extra taxes by now. I don't think that's right or fair. If that happens too much, we will reconsider," Dimon said.

JPMorgan announced plans to build a multibillion-dollar, three-million-square-foot building in London's Canary Wharf neighborhood to serve as its new UK headquarters. The building could house up to 12,000 employees, JPMorgan said in a press release late last year, and contribute $13 billion to the local economy over six years.

In the release, JPMorgan said the new building would help cement London's status as a financial center.

The question came as Starmer, whom Dimon called "very smart" during the interview, faces political pressure after recent devastating local election results for his Labor Party. Earlier this month, a consortium of UK trade unions called on politicians to raise the tax surcharge on banks' profits above £100 million from 3% to 8%.

Dimon isn't the only billionaire CEO to recently suggest that politics could shape major construction projects.

Ken Griffin, founder and CEO of Citadel, said at last week's Milken conference that plans to redevelop an office building on Park Avenue are "still a point of discussion" at his firm amid an ongoing spat with New York City Mayor Zohran Mamdani.

In April, Mamdani name-dropped Griffin in a video promoting a proposed tax on second homes in the city worth more than $5 million. The mayor filmed outside Griffin's $238 million penthouse, a move the CEO called "creepy and weird" at Milken.

Griffin's comments came after Citadel COO Gerald Beeson sent a companywide memo in April hinting that the $67 billion hedge fund might rethink its Midtown office expansion.

"We are about to commence the redevelopment of 350 Park Avenue, creating 6,000 highly paid construction jobs and supporting the creation of more than 15,000 permanent jobs in mid-town New York. The project — if we move forward — will entail more than $6 billion dollars of spending," Beeson wrote.

Griffin, a major Republican donor, moved Citadel and its sister marketing firm, Citadel Securities, to Miami in 2022. At Milken, he said Citadel had amended plans for a giant Miami tower "to make it bigger."

Though Dimon made a $3 billion bet on New York City with his global headquarters, he warned in his annual letter to shareholders that the city's high corporate and individual income taxes are inhospitable to businesses. He said that some people might leave the city, though recent data indicate that companies continued to sign leases for high-quality office space in Manhattan in the first quarter of this year.