ROME - France's presidential election will be a key test for anti-European Union sentiment and may affect the political equilibrium within the bloc, Italian analysts said.

Italian media have closely analyzed the major candidates and their respective programs over the past weeks, highlighting their crucial strong points and potential weaknesses.

They also analyzed - as did many other media outlets in Europe - the reason for the emergence of the top four contenders, two euroskeptics and two who are committed to European integration.

The latest poll shows that centrist Emmanuel Macron, far-right Marine Le Pen, conservative Francois Fillon and leftist Jean-Luc Melenchon are the four front-runners.

Besides the terror threat, which was heightened after an attack on police on central Paris' Champs-Elysee avenue some 60 hours before the polls opened, the attitude toward EU-related issues was seen as a decisive factor that could determine the final outcome.

"French (people) have to be convinced (by) immigration and Europe," Roberto D' Alimonte, a political analyst with Italy's leading business daily Il Sole 24 Ore, wrote on Friday.

Once, it was the left-right dimension that governed French citizens' attitude towards political parties and their votes, he said.

"Now it is different: immigration on the one hand, and Europe on the other hand, are the two issues that have changed the political space in France, and not only there," he said.

However, the French presidency is not the only thing at stake in the race, since the impact of its outcome is likely to reach beyond France's borders, said Edoardo Novelli, a sociologist and professor of political communication at University of Rome III.

He added that the French presidential election "is being watched in Italy and elsewhere as a sort of a key test for the recent wave of anti-European sentiment, and for the rise of far-right movements in Europe."