The battle over the landmarked, but crumbling, West-Park Presbyterian Church at Amsterdam Ave. and West 86th St. has moved onto a second front: Manhattan Supreme Court.

The tiny congregation wants to sell the 140-year-old building to developer Alchemy for $33.5 million. As Realty Check previously reported, the church has appealed to the Landmarks Preservation Commission to revoke its landmark status on hardship grounds. The LPC is expected to consider the application soon after Labor Day.

Alchemy would raze the church to build a 20-story apartment building that would include a large community center and a new facility for worshipers — a move fiercely opposed by local preservationists. Some of the activists’ views from their apartments would be blocked by the new building.

Now, the congregation is suing the Center at West-Park, a nonprofit arts facility that is a tenant at the location, for trying to extend its “null,” “void” and “unenforceable” lease, which expires in December.

The church argues in the suit that the lease, which was signed in 2018, does not give the arts center a unilateral right to renew or extend it. It moreover claims that the center is in arrears on rent and has failed to raise funds to restore the ruined building as it pledged to do — which was a key condition for giving it the far-below-market lease.

The church says it would take at least $50 million to repair the church, which has been surrounded by scaffolds for 20 years and has been closed by the Department of Buildings several times.

A church source called the arts center’s move “hypocritical. The Center was set up to help save the church [by raising restoration funds]. Having failed, they’re now trying to stop the church from doing what is needed.

“The building is literally falling apart,” the insider said.

 A lease extension, if the court ruled in favor of the arts center, wouldn’t likely thwart the sale although it could affect the timing of demolition.

The Center, backed by Council Member Gale Brewer and several local activists, has not yet responded in court.

But the organization’s lawyer, Michael S. Hiller, said the lease “expressly grants the Center the unilateral right to extend the lease terms for five years.”

He said the “bogus allegations” in the lawsuit are a “subterfuge by the congregation to avoid the promises and representations it made and to reap an economic windfall” by selling the building.

Brewer, who led the campaign to landmark the church 10 years ago, said, “Time and again, city landmarks are threatened … [by]  developers whose appetite for economic gain seems insatiable.”