Diane Abbott.

The well-known, seriously leftist, London MP - apparently a Cambridge graduate - did her morally bankrupt causes few favours when she gave an astoundingly mediocre performance on behalf of her team in the Christmas University Challenge series.
The team progressed in spite of her efforts rather than as a result of them. Even though she was tutored by Simon Schama - I seemed to know considerably more about history than she did.
Perhaps she will do better on her next appearance.