I didn't realize you were a med student in the UK (I read it, I just didn't process the information).
In that case, you'd be classed as an IMG for the purposes of matching in Canada. You wouldn't be competing against Canadian medical students, but rather other Canadian IMGs.
The advice still stands, but the case of IMGs exams
are used (at least at some programs, I can't speak for them all) to stratify applicants - specifically your score on the MCCEE and whatever USMLEs you have at that point. So do an elective at your desired program, if possible, but also do very well on your standardized exams.
Helpful hint:
It's very important to read the eligibility
criteria on the CaRMS website (more criteria
here) and make sure that you get your MCCEE and MCCQE* exams done with lots of time to spare.
*You do not HAVE to have passed the MCCQE I to apply via CaRMS - in fact, the Canadians won't have written in until May of their last year. However, if you can get it done in your fourth year this will be advantageous, since:
a) some schools use it as a filter because the number of applicants can be unmanageable b) you don't want to have to do it during your R1