It shouldn't make any difference. You can apply for a mortgage here in Canada whilst working under a temporary work permit provided you have applied for permanent residency. When you do this the mortgage company will run a local (Canadian) credit check. Some banks may insist on an international credit check for your last country of residence, if they do then simply don't go with them.
One thing you should remember is that Canada is very hot on credit within it's own boundaries. If you get bad credit here in Canada you will have to work very hard to get back up to scratch and have a good credit rating.
Hope this helps.
