PARIS France's lower house of parliament adopted a law on Tuesday prohibiting the cultivation of any variety of genetically modified maize, saying it posed a risk to the environment.
France adopted a decree last month to halt the planting of Monsanto's insect-resistant MON810 maize, the only GM crop allowed for cultivation in the European Union.
The law also applies to any strain adopted at EU level in future, including another GM variety, Pioneer 1507 developed jointly by DuPont and Dow Chemical, which could be approved by the EU executive later this year after 19 out of 28 member states failed to gather enough votes to block it.
The law adopted by the French National Assembly is similar to one rejected by the Senate, upper house, in February when it was deemed unconstitutional.
The Socialist government, like its conservative predecessor, has opposed the growing of GM crops because of public suspicion and widespread protests by environmentalists.
"It is essential today to renew a widely shared desire to maintain the French ban," Jean-Marie Le Guen, the minister in charge of relations with parliament, told the National Assembly.
"This bill strengthens the decree passed last March by preventing the immediate cultivation of GMO and extending their reach to all transgenic maize varieties," he said.
French farmers and seed firms have challenged the decree at the top administrative court, which has twice struck down similar measures, in 2011 and 2013, saying there was insufficient justification.
A debate on the future of GM policy is going on at EU level, with the European Commission suggesting an opt-out that would allow individual countries to ban such crops.
Le Guen called for a stable EU system that would ensure member states' decisions could not be challenged legally.
The ban on GM maize will head back to the Senate for approval, but even if it is rejected again, the National Assembly would have the final say.
(Reporting by Emile Picy and Sybille de La Hamaide; Editing by Janet Lawrence)