Cameron admits a hung parliament is on

The immediate answer to whether the election debates would have an impact has been answered with the sustainability of the impact now the issue. There were two possible forewarnings that this was possible. First, in previous campaigns the Lib Dem poll rating usually grew during an election campaign as they got more exposure during a campaign, the debates raised the level of exposure to a whole new level. Second, the psephologist John Curtice had highlighted some time ago that shifts from Labour to Tories were soft switchers, while they said they would vote Tory they would not describe themselves as Tory identifiers. This lack of close identification meant they had the potential to switch again. This lack of 'conversion' has also been the core failure of Cameron's period as Tory leader. However while it was possible I doubt if anyone considered it probable.

These dramatic shifts have led to David Cameron admitting that a hung parliament is a real possibility, while of course warning against it. This won't be an necessarily easy sell as other polling shows a lack of public fear of a hung parliament.