How should the Tory leadership candidates deal with Rory Stewart?

Now that Rory Stewart has gone from joke candidate to probable former spy who has a shot of making it to the final two of the Tory leadership contest, how do the other candidates deal with him? As James explains, Stewart’s best hope of getting through the next rounds is to bleed votes from Michael Gove and Jeremy Hunt.

Those two have in the past few days turned their attention from Boris Johnson and onto Stewart as they fear that he has a real chance of making it into the final two. The attack line from those candidates is that Stewart would cause a ‘polarising’ contest with plenty of ‘blue-on-blue action’ (which has the odd effect of implying that they wouldn’t spend the final round of the contest arguing with Johnson), and that he cannot unite the party.