London hasn't been the biggest city of the world since the 1920s anymore, after being surpassed by New York City, but is still the capital of Great Britain and the British Empire, and superior to Berlin in most areas: As a center of Finances, as a Harbor city, and as an administrative center. At 8.6 Million inhabitants, it's also (still) twice as big as Berlin.
In the County of London proper, there are "only" 4.3-4.4 Million people living on about 320 sq km in 1939. Since 1934, the London County Council (LCC) has been governed by Labour, even if the Conservative Party may not like it. On May 27th in 1940, Charles Latham took over the office of the "Leader" of the Council from his predecessor Herbert Morrison, when he was appointed to the cabinet by Winston Churchill.
One peculiarity makes London (in a special Way) center of the World: The Null meridian, on which Longitudes and time zones are based, goes through the Royal Observatory in Greenwich. However, Adolf Nazi wants to change this after the final victory as well.
Since 1920, the city has the airport of Croydon, which now already seems way too small.
Churchill and other British Politicians and Military leaders are very concerned about the fact that the metropolis makes a huge, defenseless target for the Luftwaffe. Already, grey anti-air defense balloons are hovering over the city. So far, there haven't been any big-scale air attacks, fortunately... to be on the safe side, many people and also Institutions like the Bank of England are evacuated.
It seems barely believable that a city with so much Tradition - founded by the Romans in the year of 50, capital of England since 1066, with the Tower, Big Ben, Westminster Abbey, the Hyde Park, The Globe, the Tower Bridge, St. Paul's Cathedral, the Universities, the Buckingham Palace, Downing Street No. 10, the Trafalgar Square, the Banks and stock markets of the City of London, the British Museum, Madame Tussauds, the tailors of Saville Row, the Wembley Football stadium, the Tennis tournaments in Wimbledon, the Press in the Fleet Street, red Doubledecker busses and black Taxis, the London Underground, Lloyd's insurance, the Abbey Road Studios, and the BBC (since 1922) might ever be surpassed, no matter whether by Berlin or New York. And yet...