France goes to the polls Sunday in the first round of an election that could decide the fate of the European Union and which is proving as unpredictable as it is important.

Eleven candidates will contest the initial round of voting. Any of four of them, spanning the spectrum from extreme-right to extreme-left, could progress to a second round of voting on May 7, when the two most popular candidates in the will face off.

To say that the election cycle has been strange doesn't do it justice: two of the leading candidates are under investigation for fraud, the favorite to win the vote has never run for office and doesn't have the backing of a major party and the current ruling Socialists are so unpopular they are likely to finish fifth behind a party created from their own extreme-left fringe - that could yet win the whole thing.

All four of the leading candidates are within 5% points of each other in the polls, well within the margin of error. That means voters could face a choice in the second round of any combination of two staunchly pro-EU market liberals and two anti-EU protectionists.

Leading in the polls, at 24%, is Emmanuel Macron, a former finance minister in the Socialist government but an independent in the election, who draws the bulk of his support from France's wealthier cities and regions. The staunchly pro-European former Rothschild's banker is promising to rejuvenate France's moribund economy - unemployment has been stuck at about 10% for nearly a decade - by cutting red tape, government jobs and state-spending.

In second place, on about 22% in the polls, is Macron's polar opposite Marine Le Pen, a far-right populist who is under investigation for diverting European Union payments to her own party. Her anti-immigration, anti-European union and protectionist policies play well with France's poorer regions and younger voters. They also terrify the markets, with analysts warning that her promise of hefty taxes on imported goods and foreign workers, coupled with 'Frexit', will usher in economic collapse in France.

A strong turn out for Le Pen in the first round could lead to an about 2% fall in the euro against the dollar, Goldman Sachs noted Friday, while her elimination in the first round could provide a 5% boost to the European currency.

In a tie for third, on 19% in recent polls, is the centre-right Republicans' candidate Francois Fillon and the extreme-left candidate Jean-Luc Melenchon.

Fillon was the early polls leader before his campaign was engulfed by a scandal over some €500,000 ($536,000) in alleged payments from the state's coffer to his wife and children for non-existent jobs, The allegations, which are denied by Fillon, pulled the rug from beneath his self-styled role as the "Mr Clean" who would target graft amongst French politicians. Politically he is about the closest thing that France has ever had to a main stream American Republican, combining social conservatism with economic liberalism centered on government job cuts.

Melenchon, meanwhile, is the election's big surprise. The candidate had been long dismissed as the unelectable fringe of the French left, but has surged to 19% in the polls from about 12% at the start of the year, following strong performances in television debates. He claims to be pro-EU but wants massive reforms to the trading bloc and has warned he will pull France out if he doesn't get his way. On the home front he wants to reduce the working week to 32 hours, cap executive pay at no more than 20 times the minimum wage, ban leveraged buyouts, break up French banks and pull France out of NATO.

Results from the first round of voting will be released Sunday evening in France, or mid-afternoon Eastern Standard Time.