As Bruce Teitelbaum pushes to get a giant housing development underway in Harlem, he is moving to eject a prominent civil rights organization from its national headquarters on the site.

The Teitelbaum affiliate behind the One45 development is pushing to evict the National Action Network, the Rev. Al Sharpton-helmed nonprofit, from its offices at 106 W. 145th St., according to a petition filed in the landlord-tenant division of New York County Civil Court.

The single-story building is among a handful of one- and two-story buildings that Teitelbaum has to bulldoze to make way for his planned 1,000-unit multifamily building, roughly a third of which is being reserved as affordable housing.

But NAN is digging its heels in, the developer alleged in court filings, potentially complicating the development's timeline, The Real Deal first reported.

To qualify for the now-expired 421-a tax break, One45 would need to deliver by June 15, 2031. The developer claims that NAN’s unwillingness to vacate the premises could jeopardize its ability to line up financing and kick off construction in time.

“Rev. Sharpton’s refusal to leave now puts 340 permanently affordable homes for Harlem families at risk — along with senior housing, union jobs, youth programs, internship opportunities, and urgently needed neighborhood investment,” Michael Cohen, the developer’s attorney, said in a statement.

NAN's lease expired two years ago, Cohen said. The nonprofit has only been able to stay in the location thanks to six consecutive lease extensions, the most recent of which expired in August, according to the petition.

NAN said it expected to be given additional renewals, given the number it had already signed, its attorneys wrote in a response to the eviction petition.

The nonprofit didn’t immediately respond to Bisnow’s request for comment. A spokesperson for the group told TRD that it had identified a new location in Harlem for its headquarters but didn't provide specifics.

This isn’t the first time that One45 has been at the center of neighborhood controversy.

Teitelbaum had pushed to develop the site during the pandemic, and his initial plan included a civil rights museum and a new HQ for NAN. But he withdrew the proposal in 2022 after the neighborhood’s then-city council member pushed for 100% affordability. The developer turned the site into a truck depot instead.

But when a new local lawmaker, Yusef Salaam, was elected, Teitelbaum built a relationship with him and put the housing development back on the table, without a new spot for NAN.

But One45 has continued to face difficulties this year. In February, the local community board requested that the building reduce the number of stories and ultimately voted against the project on the grounds that its proposed community benefits weren’t specific enough.

Its rezoning was nevertheless approved this summer by the New York City Council, with Salaam's support.