Sunday's vote in France will determine whether the pro-European centrist President Emmanuel Macron or the far-right, anti-immigration Marine Le Pen runs the European Union's second-largest economy for the next five years.
* WHO WILL WIN?
Opinion polls favour Macron to win a second term and his lead has improved since both qualified for the runoff.
But with estimates of 54%-56% of the vote for Macron, polls point to a much smaller gap than when he beat Le Pen with 66.1% in 2017, and a Le Pen win cannot be ruled out, even if it is the less likely of the two scenarios.
* WHAT WILL BE DECISIVE?
- Macron and Le Pen will face each other in a single televised debate on Wednesday evening. Le Pen's poor performance in the equivalent debate in 2017 was regarded as playing a major role in her defeat. This time round, she is expected to fare better.
- Who do voters dislike or fear the most? Neither candidate has enough diehard supporters to take them to power. So the key is to convince voters the other candidate is worse.
- What leftwing voters do will be crucial to the outcome. Macron's style and policies have upset many on the left and he will find it harder than in 2017 to get enough of them to back him to keep the far-right out of power.
* WHAT HAPPENS NEXT?
Whoever wins on Sunday will only have done so after a bitter, divisive campaign and probably with a small majority.
If Macron wins, as polls forecast, he would face a difficult second mandate, with little to no grace period and voters of all stripes likely to take to the streets over his plan to continue his pro-business reforms, including on pensions.
If Le Pen wins, a radical change of France's domestic and international policies would be expected, and street protests could start immediately.
Either way, one of the winner's first challenges will be to win the June parliamentary elections.
* WHAT ARE THE MAIN ISSUES FOR VOTERS?
- Purchasing power is voters' top concern, following a huge increase in energy prices and growing inflation. Le Pen has successfully focused her campaign on the issue.
- The election campaign started amid the war in Ukraine. Polls showed an initial boost for Macron, but that has waned.
- Surveys show voters are unhappy with Macron's economic policy, but unemployment is at its lowest in years and those polled don't think any of his opponents would do better.
- How Macron handled the pandemic could also play a role.
* WHEN DO WE KNOW WHO WON?
- Voting starts at 0600 GMT, on April 24.
- At 1800 GMT, voting ends, exit polls are published and French TV will post the picture of the winner. Official results trickle in through the evening, but the exit polls are usually reliable.
(Reporting by Ingrid Melander; editing by Barbara Lewis)