This is the website that shows constituencies showing cueing in the election. It will take some effort to look at the comparative data.
Bermondsey 2019 Electorate 93248, votes cast 58613, Labour 31723, Majority 16,126
2017 Labour majority 12972 but I haven’t got the rest of the data.
hhttps://www.bbc.co.uk/news/uk-northern-ireland-50901025are other websites to keep on file
https://inews.co.uk/news/politics/general-election-queues-polling-stations-waits-half-hour-1339774