The government is calling a review of the plans which include a smaller shop, offices and a gym.
A row is building up over Marks & Spencer’s plans to demolish and rebuild its flagship London store.
Minister Michael Gove had already ordered a review into the idea due to concerns over carbon emissions from bulldozing the building.
Now, landlords have said delaying the plans could threaten the appeal of Oxford Street to investors as a place of national economic importance.
M&S said the revamp was needed due to changing consumer habits.
It wants to redevelop the site with a smaller shop, offices and a gym.
But that plan for the 100-year-old Art Deco store at Marble Arch ran into difficulties after Mr Gove stepped in.
Earlier this week, M&S said it was “bewildered” by the planning review ordered by the Levelling Up Secretary.
A letter from landlords and property investors, which was sent to Mr Gove on Friday, said their “major concern” was that the decision would undermine “the appeal of the West End as an international centre”.
They said the West End, where the M&S store is located, draws major investors to the capital, and that London flagship stores help support “marginal stores in other British towns and cities”.
The letter was signed by Sir Peter Rogers, the chairman of the New West End Company, which represents retailers and hoteliers. It was also signed by property investors including Royal London Asset Management.
The inquiry will consider the pros and cons of bulldozing and rebuilding the store compared to refitting it. A new report will then be published with the government’s recommendations.
M&S claims a full rebuild is needed because the way people shop has changed. It said this was made starker during the Covid pandemic, when more customers opted to buy online.
The retail giant also claimed the store is unattractive and does not offer a pleasant experience for customers or staff.
M&S’s director of property, technology and development, Sacha Berendji this week accused Mr Gove of blocking “the only retail-led regeneration in the whole of Oxford Street”.
He said the building was refused listed status due to its low design quality and, while it was safe, cannot be modernised through refitting as it is three separate buildings containing asbestos.
He said that an independent assessment of the building’s carbon impact across its whole lifecycle found that a new build offered higher sustainability benefits than a refit.
“On completion, [it] will be amongst the top 10% performing buildings in London,” he added.
The revamp had been approved by Mayor of London Sadiq Khan and Westminster City Council but plans were then put on hold.
A report into the potential carbon footprint caused by bulldozing the building had warned the environmental impact would clash with City Hall’s planning guidance.
The report by architect Simon Sturgis said the plan is “absolutely crazy” and recommended refitting and renovating the existing shop instead.
Campaigners from Save Britain’s Heritage and the Architect’s Journal urged Mr Gove to launch a public inquiry into the scheme in another letter signed by top names in the industry.
This letter claimed bulldozing the historic building would “pump nearly 40,000 tonnes of C02 into the atmosphere”.
It also said the plan would destroy “an elegant and important interwar building”.
“We should be adapting the building, not destroying it,” it said.
The Department for Levelling Up, Housing and Communities said the decision to order a planning review was “made in line with established policy”.
“It is right that a project of such significance should be considered by the independent planning inspectorate and ministers,” a spokesperson said.