Mind the Gap. Three very familiar monosyllabic words for anyone who has travelled on the London Underground.

The taped announcement is a warning to beware of the potentially dangerous space between the railway carriages and the platform.

But it has a political meaning too. Any political novice will also tell you to mind the gap. Look for the space that isn’t being filled by the other parties and plug it—fast.

Well, at the moment there is a yawning chasm as the traditional parties race to head off  threats from the right and left, leaving a vacuum in the centre—the traditional winning ground.

But have the divisions that currently afflict Western societies become so acute that the centre ground is now politically unviable? We will find out—or at least be presented with a good indication— at the end of April and then again in May.

That is when the French elect their president. And it is looking increasingly as if the battle will be between the far right Marine Le Pen and her National Front Party and Emmanuel Macron’s  newly-formed En Marche  (English translation:Forward).

A few weeks ago the political landscape looked completely different. The two top contenders were Marine Le Pen and Francois Fillon. Macron and the Socialist candidate Benoit Hamon were also-rans.

Then along came Fillon-gate. It was revealed that the Republican presidential candidate paid his wife nearly a million Euros out of government money for work she never did. The revelations appear to have been a fatal blow to the presidential aspirations of Fillon and a fibulator-type boost to the hopes of Macron who overnight leapt to the number two slot in the opinion polls.

Macron has several things in common with Donald Trump. He is a businessman. He has never held elected office. His rise to power has been meteoric – private sector to economic adviser to minister of the economy in two years.

But that is where the comparison ends. Macron is young–39.  Most of all, Emmanuel Macron is a straight down the middle, pro-Europe, Free market, old fashioned middle of the road political, cultural and economic centrist liberal. When he speaks it is with the dispassionate fact-filled voice of common sense rather than the tub-thumping populist post-truth rhetoric that has come to dominate Western politics.

French voters had hoped that Francois Fillon would fill that role. But he moved the Republican Party to the right to counter the threat of anti-immigrant, anti-EU National Front candidate Marine Le Pen. Then he was caught with his hand in the till.

Socialist Benoit Hamon is campaigning on an unelectable far-left platform. At a time when the French economy is struggling to stay afloat the former education minister proposes to reduce the working week from 35 to 32 hours, tax companies using robots and wants to introduce a universal basic income. Hamon’s policies hitched to the disastrous administration of Socialist President Francois Hollande means it is unlikely that the socialists will do better than a poor fourth place.

Looming over the French political scene is Marine Le Pen. The darling of the far-right is currently holding the number one spot—27 percent according to a Valentine’s Day poll.

But France has a two-round presidential polling system.  Anyone can put their name on the ballot paper in the first round on 23rd April. And if any of the candidates achieve the highly unlikely goal of 51 percent of the electorate then they become president. If no one does—and none one ever has—then the top two candidates move to the second round on May 7th and the winner of that round moves into the Elysee Palace.

The National Front is a solid vote of determined right-wing activists, but so far they have repeatedly failed to move beyond a third of the electorate.

At the moment, opinion polls say that Macron would win 69 percent of the vote in round two run-off between Len Pen and himself. If he does, then Emmanuel Macron could  set Europe back on a liberal centrist path.

* Tom Arms is foreign editor of Liberal Democrat Voice and author of “The Encyclopedia of the War” and the recently published “America Made in Britain". He has a weekly podcast, Transatlantic Riff.