James O'Brien is Leading Britain's Conversation.
9 August 2016, 12:57
This is the moment Nick Ferrari locked horns with the union chief who is causing travel misery for hundreds of thousands of Londoners.
Paul Cox is a senior official at the RMT, who called the strike on Southern Rail.
But Nick left him unable to answer the question when he asked how just 306 people voted for the strike that is affecting over quarter of a million people.
Here is a transcript of the remarkable row: