Forty of the 96 departments in mainland France are to ask the government to declare them "agricultural disaster" zones, allowing them to release special financial aid for farmers.

More than 100 people died in France as a heatwave gripped most of Europe, and farmers across the continent have reported crop losses.

France had been counting on a bumper wheat harvest this year, but experts now expect it to fall short of last year's yield.

There was also a warning that the heat had hit lavender plantations, the fragrant crop grown in southeastern Provence, with producers warning crops would down 10-30 percent.