Communities secretary John Denham has vetoed P&O's proposal for three tall buildings in York Road because they would harm the Westminster World Heritage Site and local listed buildings including the Royal Festival Hall.
Nicknamed "the three sisters", the scheme ranges in height from 20 to 33 storeys and would create nearly 4,000 jobs and 274 homes.
Planning inspector Ava Wood presided over a public inquiry in April this year at which English Heritage and Westminster City Council set out their arguments against the proposal. The inspector recommended that the scheme be turned down.
On Friday secretary of state for communities and local government John Denham's final decision, upholding the inspector's recommendation, was published.
Whilst the minister concludes that the location is suitable for tall buildings and the P&O proposal would create improved public spaces at ground level around Waterloo Station, he is damning about the design of the three towers.
The decision letter from the Department for Communities and Local Government says: "...the secretary of state agrees with the inspector at that the success of the scheme is severely compromised by the appearance of the buildings, the way they would relate to each other and the resulting effects on their surroundings. He agrees with the inspector that, as pieces of architecture, neither Building C nor the two office towers would possess the balanced, sculptural or elegant qualities crucial to the success of tall buildings.
"He also agrees with her that, individually, the buildings would fall short of the excellence expected and, collectively, the scale of the design flaws would be heightened with far reaching concerns about the effects on the skyline, on important views and historic assets."
The minister also condemns the "fundamental unacceptability" of the architecture.
Mr Denham has ruled that the Westminster World Heritage Site would be "adversely affected" by the proposal because "the towers would materially detract from the size and importance of Big Ben ... by virtue of their bulk and disturbing aspects of design". The impact on views from Parliament Square was one of English Heritage and Westminster City Council's key objections.
Considering the scheme's effects on listed buildings on the South Bank, the minister concludes that "the setting of the Royal Festival Hall (RFH) would be unacceptably marred by the proposed development" and "the design flaws identified would cause the development to impact unfavourably on and detract from views of" the Victory Arch, the former General Lying-in Hospital and St John's Waterloo. He also notes that "the balance and dominance of County Hall would be eroded by the proposal".
The letter continued: "He considers that the scheme's potential to regenerate the area around Waterloo Station, connecting the station to the wider area, improving conditions for pedestrians and creating a welcoming and user-friendly area of public space all weigh in its favour, as do the regeneration benefits including provision of employment opportunities and housing incorporating an element of affordable units. He concludes, however, that these benefits are not sufficient to outweigh the conflict with the development plan."
In May this year he made the extraordinary claim to have intervened in the design, performed "plastic surgery" and cut the towers' height. This boast was highly dubious because the design changes predated Mr Johnson's election to City Hall. He was later forced to backtrack on this assertion.
"We are very pleased that these towers will not go ahead, as they would have been a blot on the landscape for generations to come," said Cllr Robert Davis, Westminster City Council's deputy leader and cabinet member for built environment.
"London has a unique place in history and key to its appeal is the architecture which has built up over the centuries which is why we believe it is important to protect the views of our skyline.
"We are not against the principle of tall buildings providing they are in the right place and do not damage important views, but the council objects to tall towers which will harm the settings of listed buildings and the important views from Westminster's World Heritage Site."