What would NI parties demand in a Westminster hung parliament? #BBCNolan

The General Election campaign is officially underway from today. If the opinion polls are to be believed, we're heading for a hung parliament. That means Northern Ireland politicians and parties could hold the balance of power - they could help decide who becomes the next Prime Minister. But what will their asking price be for a Westminster deal? And what should they be demanding? Stephen asks Sinn Féin's Conor Murphy, Nigel Dodds from the DUP, SDLP's Mark Durkan and UUP's Mike Nesbitt