For reference, London does not have the poorest towns/area in the UK. They tend to be seaside towns or towns in the northeast.
Of course, London is most poor when factoring in housing costs, but it is also massive compared to any other town [1]. The poorest area in the UK are the poorest in Europe [2].
1. https://www.trustforlondon.org.uk/data/poverty-rates-by-regi... (data focused on London highlights that London is the worst.)
2. https://www.theguardian.com/society/2021/jun/28/england-poor...