Deborah Grey + 12 others

Deborah Grey was the very first Reform/Alliance MP ever elected. She and 12 other Alliance MPs publicly revolted against their leader Stockwell Day, accusing him of poor leadership. They were expelled or left the caucus.

Most eventually went back to the Alliance after Day resigned. Grey later became a Conservative and served until 2004. Chuck Strahl, another rebel, eventually became a cabinet minister under Harper.