France holds a parliamentary run-off election on Sunday that will reconfigure the political landscape, with opinion polls forecasting the far-right National Rally (RN) will win the most votes but likely fall short of a majority.

Such an outcome could plunge the country into a chaotic hung parliament, severely denting the authority of President Emmanuel Macron. Equally, if the nationalist, euroskeptic RN did win a majority, the pro-business, pro-Europe president could find himself forced into a difficult "cohabitation."

Marine Le Pen's RN scored historic gains to win last Sunday's first-round vote, raising the specter of France's first far-right government since World War II.