If, as Harold Wilson said, a week is a long time in politics then two and a half years is an eternity. But that hasn't stopped commentators speculating about the result of the 2015 general election. In a notable piece for the Daily Telegraph just before the new year, former Tory MP and ConservativeHome executive editor Paul Goodman suggested that  David Cameron should abandon any hope of winning a majority (an argument I made after Nick Clegg killed the boundary changes  last August). His piece prompted a response  from the energetic Conservative chairman Grant Shapps who, unsurprisingly, insisted that the race was from over and one from his ConHome colleague Tim Montgomerie , who argued that a Conservative majority, while unlikely, remained possible.
The first YouGov poll  of the year offers evidence to support both arguments. Labour is on 43 per cent, 12 points ahead of the Conservatives (compared to a lead of just two at the start of 2012), a lead that, on a uniform swing, would see Ed Miliband enter Downing Street with a majority of 116 seats.
Poll leads, of course, can come and go. In February 1981 , Michael Foot led Margaret Thatcher by 16 points. Yet aided by the "Falklands bounce" and the splintering of the centre-left vote, the Conservatives went on to win a majority of 144 seats in 1983. But even if the Tories chip away at Labour's lead in advance of the next election (as they surely will), it's hard to see them remaining the single largest party, let alone winning a majority. The Lib Dems' veto of the boundary changes means that Labour needs a lead of just one point  on a uniform swing to win a majority; the Tories, by contrast, require one of seven. Since fewer people tend to vote in Labour constituencies, the party is able to win more seats with the same number of votes.
In the face of these daunting odds, one of the principal reasons why the Tories remain optimistic about their chances is David Cameron's consistent lead over Ed Miliband as the best prime minister. While Cameron's lead has narrowed since a year ago, when it stood at 24 points (41-17), he retains an eight-point advantage (33-25. Nick Clegg is on five per cent with "don't know" leading on 38 per cent). In the wake of his bravura conference speech, Miliband reduced Cameron's lead to four (31-27) but the gap soon widened again.
But this is a parliamentary system, you say, why should we care? The answer is that personal ratings are frequently a better long-term indicator of the election result than voting intentions. Labour often led the Tories under Neil Kinnock, for instance (sometimes by as much as 24 points), but Kinnock was never rated above John Major as a potential prime minister. A more recent example is the 2011 Scottish parliament election, which saw Alex Salmond ranked above Iain Gray even as Labour led in the polls. The final result, of course, was an SNP majority.
In an attempt to exploit Cameron's advantage over Miliband, the Tories intend to run a highly presidential campaign, asking the voters: do you want David Cameron or Ed Miliband as your prime minister? It's hard to see this overriding factors such as the collapse in the Lib Dem vote (which will gift Labour victory  in scores of Tory-Labour marginals) but it is in Cameron, who remains more popular than his party, that Tory hopes continue to reside.