New York art school hopes controversial £19m deal with developers of Extell Building will safeguard its existence for generations

It will be taller than the Empire State and will tower over the Art Students League's 'cherished old studio' - and some of its members aren't happy

Grand designs: The tower will overhang the 57th Street art school

The Art Students League of New York art school has led a charmed and magical life – it is a modest 1892 architectural jewel for working artists amid the soaring corporate skyscrapers of midtown Manhattan.

The League has nurtured many famous artists including Jackson Pollock, Mark Rothko, Georgia O'Keeffe, Norman Rockwell, George Bellows, Cy Twombly, George Grosz and Roy Lichtenstein. And in a city where a studio can cost thousands of dollars a month in rent, artists can work at the League for a fraction of that cost and have access to models, space and teachers.

It is, in short, an artist's dream: affordable studio space and classes coupled with unrivalled camaraderie and membership of an institution with an international reputation just steps from Central Park.

However, all is not well at the League, and it is the institution's location – in the middle of some of the world's most expensive property – that is causing discord. The League's brownstone base in 57th Street is just a few storeys high, and is protected by New York's landmark preservation regulations. But what is built around it is another matter.

There are plans to erect one of the tallest buildings in the world next door, which will make the Art Students League look like a Victorian doll's house. At 1,423ft, (433.7m) the Extell Building will be taller than the Empire State Building and just 60ft shorter than the Petronas Towers in Kuala Lumpur, Malaysia.

The League hopes to pocket $31.8m (£19.3m) from the Extell developers in return for allowing them to add a huge cantilever of apartments that would stick out 30ft to the side of their tower and hang over the League from 30 storeys above.

The League calls the deal a "once-in-a-lifetime opportunity" that will safeguard its existence for generations, allowing it to keep tuition fees low, improve and modernise. However, a growing number of League members are trying to delay the 12 February vote on the deal. They claim that the League is rushing members into something they may regret. Sceptics want more time to weigh up the proposals and consider any possible danger to the League's building or its members during the five-year building period and after the tower is completed.

"The blind faith in our board from some of the members I've known for years is maybe the most maddening aspect of this," said Robert Holden, a League life member. "Our cherished old studio building... is falling apart. Wait till Extell starts blasting."

However, some League instructors and members have already voted for the deal. "The financial benefits from this agreement will preserve the League and its traditions," wrote board president Salvatore Barbieri and executive director Ira Goldberg in a 46-page glossy brochure urging members to "Vote Yes For 31.8 Million Dollars".

League members cannot stop the tower going up, but they could block the overhanging cantilever or force more analysis of the plan. "The League is too beautiful and too venerable to be messed with like this," said member Beth Karts. "Some things in this world, like the League, are worth a lot more than money."