Developers Qatari Diar Real Estate withdrew their planning application for the prestigious Chelsea Barracks site after Charles wrote to the chairman, who is also the prime minister of Qatar, saying that his "heart sank" when he saw the design.
But Sir Michael Peat defended him, saying he was voicing the views of "ordinary people" after concerned local residents contacted him.
He said: "The Prince of Wales was contacted by local residents who were concerned about the proposed development. They asked him to do what he could to ensure that their views received exposure. Their views did represent the views of the majority."
The Prince's willingness to intervene has drawn criticism from the world of architecture.