Conversation so far:
When did David Cameron become special adviser to the chancellor?
David Cameron became special adviser to the chancellor in 1992.
Who was the chancellor David Cameron became special advisor to?
David Cameron became special advisor to Norman Lamont
How long was David Cameron special adviser for Norman Lamont?
David Cameron was special adviser for Norman Lamont from 1992 to 1994

Question: Why was Lamont fired?
Self-contained rewrite: Why was Norman Lamont fired from the chancellor position?