Richard Seifert's 1967 Drapers' Gardens tower in the City of London (pictured) remains under threat, following arts minister Baroness Blackstone's decision not to grant the building listed status.
The Twentieth Century Society - which has attacked the judgement - applied for a spot listing in June after the corporation gave planning consent to a Foggo Associates scheme that includes the demolition of the 99.5m tower.
The practice wants to replace the existing structure - considered by the society to be a better example of Seifert's work than Centre Point - with an 18-storey skyscraper.
Blackstone removed the last legal hurdle to the Foggo scheme because 'Seifert's building is not historically or architecturally significant enough to warrant listing', despite a report from English Heritage calling for it to be given Grade II status.
But Twentieth Century Society director Catherine Croft said she was 'really disappointed' with the decision as 'we consider it a really fine example of design and sufficiently different to Seifert's other work to be worth saving'.
She claimed the ruling is a prime example of ministers taking into account the economic merits of a building over its architectural importance.
And Croft added that many, including Blackstone, fail to understand that listing is 'not just about freezing a building in time', it is a way of encouraging developers to work within existing structures. 'This is certainly the situation with this decision, ' she said.
Drapers' Gardens could still be reprieved, however. Foggo Associates' client, the Royal Bank of Scotland, is undertaking an internal review that could affect the future of the scheme.