Selfridges has thrown in its support for neighbouring Marks & Spencer as an inquiry into the latter’s redevelopment plans for its flagship Marble Arch store begins.

Marks & Spencer wants to raze and rebuild its 90-year-old landmark Oxford Street store, arguing that refurbishment of the three buildings that form its Marble Arch store is not feasible, potentially forcing it to relocate.

Its plans have proved controversial, however, and the two-week inquiry, which started on 25 October in Westminster, will hear from environmental campaigners and heritage advocates, who argue that the building should instead be refurbished.

Central Group and Austrian real estate company Signa Holding bought Selfridges in September. In a letter to the Planning Inspectorate, the retailer said it “supports and endorses” the redevelopment, per The Guardian.

Selfridges added the plans play a role in “maintaining Oxford Street as the U.K.’s national shop window”.

The planning inquiry will put consideration of the carbon footprint of a major building redevelopment centre stage for the first time. It will be overseen by planning inspector David Nicholson, who recently blocked the proposed Tulip Tower in London, in part because its “highly unsustainable” use of concrete might set a precedent.

Arguing for the scheme’s sustainability credentials, M&S said the new development, designed by architect Pilbrow & Partners, will use a quarter of the current building’s energy, with an ROI within 17 years of its 100-year-plus expected lifespan. It has also pledged that 95% of the existing building's materials will be recovered, recycled or reused.

Opponents have countered the scheme would release almost 40,000 tonnes of carbon into the atmosphere.

Former government Communities Secretary Michael Gove announced an inquiry in June, despite approval by the local council and the Greater London Authority.

Since then, Westminster City Council has switched from Conservative- to Labour-led. The new administration has welcomed the inquiry and said it is “serious about reducing the environmental impact of new development,” but also does not want M&S to move.

Oxford Street has already lost the Debenhams and House of Fraser department stores, while John Lewis has plans to downsize its store and convert space to offices.