ATG reported in August that seven of the 22 galleries on the street, in the heart of the West End's commercial gallery district, were informed that their leases would not be renewed next year because of redevelopment plans by a new landlord, Native Land.
Now, five more galleries - Petley's, Messum's, Bernard Jacobson, Hay Hill and Medici Gallery - are facing relocation as landowner the Pollen Estate have announced plans to redevelop numbers 5-9 Cork Street after the galleries' leases expire in 2015.
Plans for both projects will be submitted to Westminster Council in late October, with a decision likely early next year. Both propose retail units at street level and dealers expect that rents will rise sharply, leaving them unable to compete with the fashion and luxury goods chains who already dominate neighbouring Bond Street.
Native Land's proposal includes replacing the current building with luxury apartment blocks, with art galleries and restaurants at street level. Pollen Estate want to demolish one 20th century building (number 7, now home to the India Tourist Office) and knock down all but the facade of the remaining buildings. The street level gallery space will then be remodelled from six small units into four larger ones.
A spokesman from Pollen Estate told ATG: "The proposals for 5-9 Cork Street will provide new office, retail and art gallery space, enhancing the appearance of the Mayfair Conservation Area and upgrading the quality of accommodation available. The Estate is keen to preserve and build on Cork Street's reputation as a gallery location by providing higher quality space with an improved frontage that will be completed late 2016/2017."
They continued: "Gallery owners affected by the proposals are being consulted beforehand to give them a first-hand opportunity to comment and for us to listen to feedback on the design proposals. Finally, with development completion still more than four years away, we will determine our leasing policy nearer the time, and once we have secured planning and any related consents."
Online Petition
Opponents of the Cork Street redevelopment plans are many and an online petition has already exceeded the target of 10,000 signatures needed to take the issue to Parliament.
One way that the businesses might be protected is if the street was awarded Special Policy status, protecting the art and antiques galleries deemed synonymous with the area - as has happened with tailors on Savile Row and the private clubs and art galleries in St James's.
Councillor Jonathan Glanz recently gave his response on the issue on the petition site: "As ward councillor I have had a number of meetings with those representing the Arts businesses in the street and the area around it and am aware of the pressures on smaller galleries in particular.
"I believe there is a proposal being formulated to seek to designate the area as one of Special Policy on behalf of the arts and antique businesses in the same way that Savile Row is the subject of a special policy that relates to bespoke tailoring. This would seek to protect such uses under planning law.
"I believe the contribution that the arts businesses, big and small, working alongside the major auction houses make to the area is very important and support the continuance of such occupiers which is part of what gives the West End its unique character."
Gallery owners on both sites feel the landlords are taking a shortsighted view, destroying the very reason that visitors come to the area.
"They are gutting the whole street and have priced us off the road," said Tom Dawnay of Medici Gallery, one of the five Pollen Estate galleries facing relocation in 2015. "They may as well roof over the whole of Mayfair and call it Westfield Central. It's becoming so homogenised. We just hope that by campaigning against it the council will be sympathetic to cultural consideration."
Most of the dealers affected hope to remain in Mayfair but are weighing up their next move. "It's the million-dollar question - where do we move to? It's almost a question of who moves where first," said Mr Dawnay.
