Debate: "A hung parliament would be hell"

What are the arguments? I tried to do as much justice as possible to the anti-hangers on this IntelligenceSquared written debate - click through the image below for the detail. Laying it out like this, with every concession made to the anti's and wanting to give them the best arguments they can have makes it quite clear the type of politics the anti's are defending: managerial, anti-democratic and ultimately tinged with authoritarianism. (The full text is here, or click on the image below).