Prominent names in the contemporary art world are fighting to save the Russell Page-designed viewing garden at New York's Frick Collection museum.

The tiny garden stands in the way of a planned expansion designed by Davis Brody Bond, the firm that recently completed the 9/11 Memorial Museum. The artist Rachel Feinstein helped rally luminaries such as Chuck Close, Cindy Sherman, Brice Marden, Cecily Brown, and Frank Stella, as well as filmmaker Sophia Coppola and fashion designer Marc Jacobs to block the project.

Completed in 1977, the viewing garden is located mid-block on East 70th street. It was created as a part of an expansion that also included a small reception hall, and is designed in a highly pictorial style with a reflecting pool, ornamental plantings and several mature trees. It is intended to be seen from the street and from inside the museum's reception hall, and is not accessible to visitors.

The garden was designed by late British landscape architect Russell Page, who died in 1985. Hailed as "one of the founding fathers of landscape architecture", Page's Frick Collection space – his only project realised in New York City – is regarded as one of his most important works.

Originally the home of industrialist and collector Henry Clay Frick, the Frick Collection has been extended several times over the decades. The new expansion would add a new gallery for temporary exhibitions as well as improved visitor services facilities including ticketing, cloakrooms, and a cafe and shop.

Offices and administrative spaces would be moved to new spaces above, allowing the museum to open up more of the old mansion to the public – a velvet rope currently prevents visitors from ascending the grand staircase that leads up to the former bedrooms.

Opponents believe the expansion will destroy Page's garden and forever alter the experience of the Frick, a museum known for its collection of masterworks by Rembrandt, Vermeer, Piero della Francesca and James McNeill Whistler, among many others.

The group of contemporary artists sent a letter to New York City mayor Bill de Blasio and Landmarks Preservation Commission chair Meenakshi Srinivasan urging them to block the expansion.

"The ensemble the Frick wishes to raze, composed of the Reception Hall Pavilion and the Russell Page-designed Viewing Garden on East 70th Street, is a masterstroke of the evolving museum's design, positioning the mansion in counterpoint to the Manhattan street grid, and optimising the 'house museum' experience," they wrote in the letter.

"Replacing the hall and garden with an institutional 106-foot tower will indeed destroy the famed Frick experience for artists and art lovers around the world."

Museum officials responded to the artists' letter with the following statement: "The fact is that our plan will not compromise the Frick's intimacy but will enhance it. The existing galleries will remain unchanged and for the first time a portion of the second floor of the historic mansion will be opened to the public as new permanent galleries."

Page is the subject of an exhibition at London's Garden Museum named The Education of a Gardener – also the title of a book he wrote on the subject in 1962 – which is view until 21 June. New York's Landmarks Preservation Commission has the power to approve or reject the expansion scheme, and it has yet to indicate any position on the project to date.