It's almost crunch time for Theresa May as she prepares for the Commons vote on her Brexit withdrawal agreement. The numbers do not appear to be on her side. It's thought as many 100 Conservative MPs are planning to vote against it. The government's chief whip is Julian Smith. It's his rather daunting job to persuade rebel Tory MPs to vote with the PM. Can he do it? We look for clues in his life story so far.

Producer: Oliver Jones