Iain Duncan Smith has threatened to resign from the Conservative Party and sit as an independent MP, The Sunday Telegraph has learned. Mr Duncan Smith, still bitter about being forced to resign the leadership in October 2003, told colleagues that he will take the extraordinary step if two people he blames particularly for his downfall are allowed to stand as Tories at the next election. Vanessa Gearson and Mark MacGregor played leading roles in the "Betsygate" affair which saw Mr Duncan Smith accused of sanctioning improper payments to his wife. Both fought last May's election unsuccessfully and are understood to...