Why does the French election matter? If you're coming into to this without too much background, which is totally understandable given Britain's facing it's own election in a matter of weeks, here's just a few reasons why the French election is worth paying attention to:

Risk of 'Frexit'

Most of the 11 candidates are campaigning against the European Union, blamed for myriad woes. Two with a chance at the presidency, far-right Marine Le Pen and far-left Jean-Luc Melenchon, could seek to pull France out of the union and its shared euro currency altogether.

A French exit of either would be far more far-reaching than Britain's - it could spell death for the EU, the euro and the whole idea of European unity borne from the blood of World War II. France is a founding member of the EU, and its main driver along with former rival Germany.

Financial markets are already jittery over a possible Frexit, fearing controls on money transfers, capital flight, a plague of defaults and lawsuits on bonds and contracts. Ms Le Pen's team downplays apocalyptic scenarios, arguing that the euro is headed for a breakup eventually anyway.

Ms Le Pen and Mr Melenchon also blame free trade pacts for killing French jobs and want to renegotiate them, which would cause a financial tangle for the rest of the EU and France's trade partners.

Trump and populism

If Ms Le Pen or Mr Melenchon reach the second round, it will be seen as a clear victory for the populist wave reflected by the votes for Donald Trump and Brexit. Many French workers who have lost out because of globalisation are similarly fed up with establishment parties and especially attracted by promises of ditching the status quo.

Alternatively, if neither candidate makes it past Sunday's first round into the May 7 runoff, that's a clear message that populist nationalism is receding.

Centrist Emmanuel Macron and conservative Francois Fillon are committed to European unity and would reform labor rules but not make any drastic moves. Mr Macron has framed himself as a bulwark against Trump's protectionism.

Assad's Syria and Putin's Russia

A nuclear power with a seat on the UN Security Council and tens of thousands of troops around the world, France is a key US ally in the campaign against the Islamic State of Iraq and Levant (Isil) group and major diplomatic player.

Mr Macron would likely keep up the French operations against extremists in Iraq and Syria and Africa's Sahel region - and keep up pressure on Russia over Ukraine and its actions to bolster Syrian President Bashar Assad.

The other three front-runners, on the other hand, had supported restoring dialogue with Assad to find a political solution for Syria. Ms Le Pen firmly backs Assad and distanced herself from Trump over recent US airstrikes targeting Assad's regime.

Ms Le Pen also met recently with President Vladimir Putin and would push for lifting sanctions against Russia over the conflict in Ukraine.

Mr Fillon too has been friendly with Mr Putin in the past, but has taken a harder stance lately - notably since chemical weapon attack blamed on Assad's forces.