The 2015 election will not see one party sweep to power by making gains right across the country. Success will be localised. A party might do incredibly well in one corner of the UK, but dreadfully badly in another. An advance in one region may be paralled by retreat in another.
This seems particularly true for Labour, who could end up in office thanks to the most inconsistent election-winning performance by a major political party in modern history.
I’ve drawn up a list of 12 seats that will serve as a guide to Labour’s fortunes, both at the polls and during the campaign.
Each of the 12 represents a particular kind of contest, a litmus test if you like, the result of which will provide a measure of Ed Miliband’s success – or failure.
I’ll do the same for the Conservatives and Liberal Democrats, both of whom are set for similarly inconsistent elections. But first, here is my pick of Labour’s decisive dozen.