The Brexit border battle has begun. Could stand off between London, Belfast and Dublin really bring down Theresa May's government? @JohnODowdSF reacts

Are we now reaching the crunch point in the Brexit negotiations? And who will blink first? It's an extraordinary stand -off between London and Dublin over Northern Ireland's position post-Brexit. Westminster's Brexit committee says the two positions aren't compatible. And the DUP's Sammy Wilson has fired a warning to Theresa May. And Tanaiste Simon Coveney says the UK can't have it both ways. So - where does this leave Northern Ireland - and the border - at a time when there's no Executive here? Stephen spoke to Sinn Fein Brexit spokesperson John O'Dowd.