We're less than a week away from the first round of the French presidential elections, which in theory could see one candidate declared the outright winner if they secure more than half of the vote but will in practice send the top two candidates through to a run-off round.

As to who that top two will be, that's harder to call. There are four candidates each polling just under a quarter of the vote: dashing centrist Emmanuel Macron, scandal-ridden right-winger François Fillon, tub-thumping leftist Jean-Luc Mélenchon and the far-right's Marine Le Pen. All are within the margin of error of making the top two.

The polls say that Macron beats everyone, Mélenchon beats everyone but Macron, Fillon loses to everyone but Le Pen, and Le Pen is defeated by all three, with varying margins, with Macron securing the biggest victory, then Mélenchon, and then an uncomfortably tight showing for Fillon. So as far as stopping Le Pen goes, there's a clear order of preference: Macron, Mélenchon, and Fillon. (The question of how France is run after that is another topic.)

A couple of things to note. The first is that Mélenchon underperformed the polls in 2012 and may do so again. The second is that Fillon and - to a lesser extent - Macron are doing best among the elderly and other groups most likely to vote. If there is a polling shock Fillon is most likely to be the beneficiary.

The third is that whoever is President will have to cohabit with the winner of the legislative elections in June, likely to be Fillon's mainstream conservatives. Macron and Mélenchon will both struggle to deliver their promises as a result. Le Pen's current poll position owes much to the failure of François Hollande's presidency to get anything done. The difficult parliamentary backdrop for the centre and far-left may mean that she gets another, better crack at the top job in 2022.