The 5:30 p.m. event caps off a five-state fundraising swing this week for the Harris-Walz campaign.
Grammy-winning British folk band Mumford & Sons is expected to perform at the fundraiser.
It's being held at the at the 17,000-square-foot Coopers Neck Lane home of Stewart Butterfield, co-founder and CEO of messaging company Slack, and Jen Rubio, co-founder and CEO of Away, a luggage manufacturer and retailer.
"This will be the Governor's first event in New York for Harris-Walz 2024, and we are looking forward to gathering a group of energized supporters for the campaign ahead of the DNC convention," they said.
Donors will pay $50,000 to attend, and $75,000 for a photo op with Walz and access to a "VIP reception."
Meantime, Second Gentleman Doug Emhoff will be appearing in Sag Harbor and Water Mill later this month. Commerce Secretary Gina Raimondo is set to attend an event on August 31.
On the Republican side, Senator JD Vance is set to attend a high-dollar fundraiser in Southampton next weekend, according to a copy of the invitation obtained by ABC News.
The event is set to be hosted by a number of big-name Trump donors, including billionaire hedge fund manager John Paulson and Omeed Malik, the president of the investment firm 1789 Capital.
Trump's former secretary of commerce, Wilbur Ross, is also listed as a host for the fundraiser, which is billed as an "afternoon event with the next Vice President of the United States."
The event, next Sunday, is expected to raise millions. Tickets to the roundtable event cost $25,000, with an "attendee" ticket going for $5,000. Inclusion in the host committee costs $50,000 per person.
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