English Heritage has urged Southwark Council to reject plans for a 21-storey tower close to Tate Modern because it will detract from views of St Paul's Cathedral from Alexandra Palace.
Earlier this month we reported on concerns expressed by Mayor of London Boris Johnson that Delancey's development at 185 Park Street will have a negative impact on impact on "local views and the character of Bankside".
Now a letter from English Heritage – which predates the Mayor's intervention – has been made public.
The heritage watchdog's concerns relate to the protected view of central London from Alexandra Palace.
"From the submitted visualisations it is clear that the proposed development will be distinctly visible in proximity to the western towers of the cathedral, and of roughly equivalent height," wrote Matthew Cooper of English Heritage in a submission to Southwark planners.
"The necessity of clear space around the towers is integral to the legibility of the cathedral as a whole.
"Without this the focus of the view becomes only the dome, drum and peristyle of the cathedral, greatly reducing the importance of the protected vista.
"Should the proposal be realised the recognition of the towers will be diminished, thereby reducing the viewer's ability to recognise and appreciate the landmark as a whole.
"This proposal does not comply with policy and as such English Heritage recommends its refusal."