Southwark is a young and ethnically diverse borough with a high proportion of people living in rented or unstable accommodation and/or doing a low skilled job, on a low income or benefits. Each of these factors decreases the likelihood of voting, especially when they intersect, as they so often do in the borough.
There are still almost 2 weeks left to register to vote and Southwark CAN has a useful webpage with info on registering, local candidates and local hustings to get people involved - take a look.
In Southwark homeless people or those in temporary accommodation are very unlikely to be registered, often because of the myth that a fixed address is required to vote. Some work is being done to correct this misinformation, but it often prevails. To register to vote without a fixed address or help someone else to see full details HERE.