Campaigning in Wembley Central

Out in Wembley Central at the weekend, I was struck by the lack of canvassers from the other parties.  We had a large group, and covered quite a swathe of the local roads, yet we saw no signs of other parties.  I believe that there have been a number of leaflets, but the lack of canvassing is quite a contrast to previous by elections, including the quite recent one in Kenton.