There is a battle brewing over office space on Manhattan’s West Side between two of the world's tech behemoths.

Both Apple and Facebook are eyeing leases for the entirety of Vornado’s Farley Post Office redevelopment, which has put the publicly traded real estate firm's chairman, Steven Roth, in a tight spot, The New York Post reports.

Facebook has been hunting for space in the city, and was said at one point to be considering a monster lease at 50 Hudson Yards. However, the social networking company has decided it wants to lease the 740K SF of office space at the Farley building, per the Post.

The issue is Apple, also on the prowl for office space, has also toured the building — and "suddenly decided" it wants the space — the redevelopment of the landmarked building that would be connected underground to Penn Station — for itself.

Roth is reportedly favoring Facebook, which already leases space at Vornado’s 770 Broadway. It also has reportedly leased space at 335 Madison Ave., owned by Milstein Properties.

“It changes every week,” an unnamed broker told the Post. None of the companies involved commented.

There is also another player in the mix: Amazon, which was said to be looking at the Farley Building, too. The e-commerce giant is looking to lock down space in the city, and locations like Brookfield’s Two Manhattan West and WeWork’s Lord & Taylor building on Fifth Avenue are also rumored contenders.

The Lord & Taylor building, however, has reportedly become a major pain point for WeWork — and some reports suggest Amazon was never considering space there, and favors a 400K SF lease at SL Green’s 460 West 34th St. development, a deal that is said to be close to final.

With Facebook apparently in the lead for the sought-after Farley building, sources told the Post Amazon and Apple are looking at the Morgan North Postal Facility, where Tishman Speyer is turning the upper floors into 630K SF of creative offices.