The Labour Party and particularly Jeremy Corbyn have tried to make political capital out of a homeless man who was found dead at Westminster tube station last week.
The by-election is due to take place on February 23. Eligible voters have until midnight on February 7 to register in time to take part in the by-election.
Labour retained the seat in 2015 with a majority of 5,175 over UKIP with the Conservatives a further 33 votes behind. Labour has held the seat since its creation in 1950.