If you recall the now famous "Does Sheffield have the most Football League clubs" thread, you'll remember that it was proven that Greater London is not actually a city, and that in that area, there are only two official cities: West Minster and City of London
http://www.urban75.net/vbulletin/showthread.php?t=251956&highlight=sheffield
True. I was disputing isitme's claim that London wasn't "English" rather than a more technical debate about what, precisely, consitutes "London", though...