Key constituencies to watch today
Donegal and South Dublin: Lowest turnout and highest No usually in Donegal North-East and Donegal North-West, while the highest turnout and highest support for Yes is invariably in Dublin South and Dun Laoghaire.
Dublin West: The base for both Socialist TD Joe Higgins and Labour Party director of elections Joan Burton.
Clare: Not the best ground for a Yes vote in EU referenda, so if it passes here, it'll pass overall.
Cork South-Central: Better vote Yes or else there'll be embarrassment for Fianna Fail leader Micheal Martin and Fine Gael director of elections Simon Coveney.
Mayo: Enda Kenny can win four seats out of five in his home county for Fine Gael, but will that translate into Yes votes?