I would like to add to your comment and highlight that this isn't similar to 2007-2008 as those loans were made to people who should never have gotten them in the first place and had no hope to pay it off. Those loans were straight up losses, whereas here, the loans are still good and some companies are even earning interest by delaying mortgage payments. But if too many people stop paying at the same time, the system will collapse and we'll have a repeat of GFC.
City of London is one of the central boroughs of London. It's basically the historic city, now turned into a financial district. So I wouldn't say that's the correct answer either.