Another twist in the Adam Afriyie stalking horse plot this morning. Today’s headlines report that the PM has been set a deadline of summer 2014 to improve the party’s poll ratings or face a vote of confidence. Not only that but the Chancellor is now in the plotters’ sights as well. Guido knows of at least two Tory MPs who have received dinner invites from Afriyie as part of a concerted effort to woo potential backers. It’s on…