Prince Charles: 'You can't be the same as the sovereign'

The Prince of Wales has said that he will have to change his approach to public life if he becomes king.

Speaking to a BBC documentary to mark his 70th birthday, Prince Charles said that it would be "nonsense" to think a king could campaign on issues in the same way an heir could.

Prince, Son and Heir: Charles at 70 is on BBC One at 21:00 GMT.