Architecture campaigners looking to create a £20,000 fighting fund to oppose retail giant Marks & Spencer’s plans to redevelop its flagship branch have raised one-third of the cash in a matter of days.

Save Britain’s Heritage set the target to help cover its legal costs at the public inquiry into M&S’s proposals to replace its Marble Arch store on Oxford Street with a much larger Pilbrow & Partners-designed scheme.

The proposals were approved by Westminster City Council in November, but they were called in by then-housing secretary Michael Gove in June. A government minister will ultimately determine whether the plans can proceed, based on the advice of the planning inspector who presides over the public inquiry.