At a meeting on 5 November France was one of nine member-states that voted against the European Commission's proposal of a five-year renewal because a report by the World Health Organisation's (WHO) cancer-research centre concluded that glyphosate was "probably carcinogenic".
Five others abstained and 14 voted for, but to be passed the motion must have the support of 16 states representing 65 percent of the European Union's population.
Although higher-level officials were to be present at Monday afternoon's meeting, the change was a surprise.
Earlier there had been no signs of anyone changing their stance, Germany saying it would abstain again and France proudly announcing its continued opposition to anything longer than three years.
"Considering the risks, France will oppose this proposal and vote against," French junior minister Brune Poirson saying France would told the Journal du Dimanche newspaper. "France wants to build a phased exit from glyphosate and, with several partners, thinks that a shorter timeframe would be possible."
The European Commission's initial proposal of 10 years, later reduced to five, was based on a report commissioned by the EU's food safety body, which, despite the WHO body's findings, gave glyphosate a clean bill of health.
Cut and paste report
But NGOs have revealed that large parts of that report were cut and pasted from Monsanto's own submissions to the inquiry, giving rise to questions not only about the report itself but also about the method employed to compile such documents.
In September Austrian NGO Global 2000 showed that about 100 pages of the report were identical to documents submitted by Monsanto.
France's Le Monde newspaper on Monday confirmed that a report on genotixicity commissioned by Monsanto featured word for word in the European report.
Although the report was supposedly one of the independent "critical summaries" that companies are supposed to provide, Le Monde found a comment from its author in leaked Monsanto documents that his work would be of great help in defending Roundup against accusations that it can harm human genes.
At a hearing at the European parliament in October, the head of the food-safety agency, José Tarazona, said the report's critics simply did not understand how such studies are compiled.
Companies are invited to submit their own reports as well as some critical summaries, he explained, and experts are asked to verify the scientific conclusions.
The actual report is compiled by an institution of whatever country is designated "reporter state", in this case Germany's risk-management agency, BfR, which, like Monsanto, declined to attend the hearing.
Companies choose both sides
Many in the audience were astonished to learn that companies hoping for authorisation are allowed to choose not only the case for their product but the case against as well.
"Three-quarters of the 60 genotoxicity studies published in the scientific literature have reported that glyphosate or glyphosate-based herbicides damage DNA," Global 2000's Helmut Burtscher told Le Monde.
Faced with accusations of plagiarism, given that the origin of the cut-and-pasted sections was not indicated, the BfR was unapolgetic.
"When the applicants cite studies correctly or interpret these studies correctly from a scientific and methodological perspective ... ," it said in a statement, "the European assessment authorities have in the past had no cause to rewrite these statements in the numerous authorisation and approval procedures for plant protection products, chemicals and medicines."
In the light of the revelations a group of left-wing and Green Euro-MPs are demanding a special committee to "improve the authorisation process for pesticides".