Hello we are on a work permit at the moment and living in ontario, canada and applied for permanent residency in the uk and are now awaiting the london high commission to ask us to send our passports to them, we have had the medicals done and paid for right of permanent residency.
My question is, once we receive our passports back, do we have to leave canada and re-enter again and land as permanent residents and if so, can we drive over the border and do this or is there another way of doing this?

thanks to you all

Thats exactly what you have to do. Many people have reported their experiences doing this so called flagpole landing.....leave Canada as a temp resident, drive around the flagpole and come back into Canada as a PR.

Good Luck