https://secure.cic.gc.ca/enquiries-renseignements/case-cas-eng.aspx?mission=London&AspxAutoDetectCookieSupport=1
This is the link for London visa office.
However, I had to write to them twice to get the details. The first time I wrote to them was a generic enquiry on my application status to which I received a generic reply in less than 24 hours.
The second time I wrote to them, I explained why I wanted to know my application status as my UK visa expires soon so I would have to extend it and if I do, I might not be able to land in Canada while my UK visa application is under consideration, which is a bit complex situation. This time they replied to me with these details after nearly 25 days.