King Charles will walk a diplomatic tightrope as he opens Canada's Parliament for the first time, 48 years after his mother.

The King's mother, the late Queen Elizabeth II, was the last monarch to open Canada's Parliament in 1957 and was also the most recent to deliver the "speech from the throne" in 1977, in a ceremony that marks the start of a parliamentary session.

It is extraordinarily rare for the monarch to deliver what’s called the speech from the throne in Canada. Charles’ mother, Queen Elizabeth II, only did it twice in her 70-year reign. The last time was in 1977.