I found my Pevsner City of London guidebook (1997, updated by Simon Bradley). It says that A.J.Myers was the principal architect and continues as follows:
"Denounced immediately it went up for the damage its nine-storeys and square-towered skyline inflicted on views of St Pauls; protective legislation swiftly followed. Classically detailed, attempting playfulness in the Lutyens way, but spread too thin."
If this building had been built elsewhere it likely would not have been controversial. In an odd sort of way, the austere form and massing resembles a mini Battersea Power Station, though with Classical rather than Art Deco detailing, and no chimneys sitting atop the corner towers.
During WW2, as the hub of international telecommunications, this was one of the most important buildings to protect and had people on the roof throughout the blitz to put out incendiary fires, with an addition constructed during the war with a very thick protective concrete roof. Some refer to it aa a citadel.
It may not perform such a strategically important role today but no doubt it is still a nexus of London's telecommunications so likely remains in use for such purposes in some way.
