I have no doubt Manchester United would be interested, given the culture of the club needs to change signing the England Captain is possibly the most effective and quickest way to do that.
That said, whilst I'm sure his relationship with Levy will forever be fractured as a result of broken verbal agreements, but is there really any point in making a sideways step to Manchester United? If he can't win trophies at Tottenham, is he really going to win any at Manchester United? You'd have to say Spurs are in the better position under Conte to do so.