French voters are choosing their next President on Sunday after an unpredictable campaign that has divided the country.

The second round contest pits centrist Emmanuel Macron, a former investment banker, against the far-right nationalist marine, Le pen.

Citizens in some overseas territories and many French expats abroad have begun voting.

The polls opened in metropolitan France in the early hours of Sunday, even as polling stations will remain open in some big cities until later in the day with early estimates of the result due to be reported immediately after they close.

The two candidates, who topped a field of 11 presidential hopefuls in the first round election on April 23, have offered voters starkly different visions of France.

The run-off will be keenly watched across Europe, ahead of elections in Germany and the UK and as Britain negotiates its exit from the EU.

Meanwhile, both candidates have cast their votes.