It's been described as "the last bastion of free speech in the Western world," and over the past two centuries the world-famous Oxford Debating Union has certainly lived up to its name, with a series of landmark and inspirational addresses.

But among the politicians of tomorrow and major world figures such as Malcolm X and Mother Teresa, a sprinkling of more unusual keynote speakers have been persuaded to the podium. From porn stars and glamour models to cartoon characters, read on for details of pop culture guests who have spiced up the legendary Oxford University debate floor over the years...

Picture credits: Rex Features

10 unlikely Oxford Union speakers