Activists on Monday handed the EU a petition signed by more than 1.3 million people calling for a European ban on the weedkiller glyphosate, produced by chemicals giant Monsanto and others, over fears it causes cancer.
The petition was given to the European Commission, the executive of the 28-nation EU which has recommended the license for the herbicide be renewed for ten years in mid-December.
"The first action is for the European Commission not to reauthorise glyphosate," Greenpeace EU director Jorgo Riss told reporters after handing the petition to commissioners.
"This would mean a de facto ban of glyphosate in Europe," Riss added.
European Commission spokesman Margaritis Schinas told a news conference that commissioners invited the activists to explain "their ideas in more depth" while the European Parliament will hold public hearings in the next few weeks.
Experts from the 28 member states are due to vote on the commission recommendation on Wednesday, but Greenpeace said it is unclear whether Brussels will get the majority support needed for it to pass.
Greenpeace and other activists said they had attained the signature threshold to require a formal response from the European Commission -- one million names from at least seven countries -- in a record time of five months.
The citizens initiative also called on the EU only to base decisions using peer-reviewed research and stop allowing chemical companies to decide which research labs carry out studies.
"The system in Europe is neither transparent nor independent," Riss said.
The weedkiller deadlock in the EU has dragged on since June 2016, when its previous 15-year licence expired, and an 18-month extension was granted.
The commission earlier this year recommended renewing the license after the European Food Safety Authority (EFSA) ruled that glyphosate should not be classified as a carcinogen.
But the ruling has failed to ease concerns among member states and among the public.
Opponents of glyphosate, led by Greenpeace, point to research from the World Health Organization that concludes it may be carcinogenic, and are calling for an outright ban.
A 2016 review carried out by other WHO experts and the UN Food and Agriculture Organization said "glyphosate is unlikely to pose a carcinogenic risk to humans from exposure through the diet".
Monsanto maintains glyphosate "meets or exceeds all requirements for full renewal under European law and regulation" and charged that the renewal procedure has in "many respects been hijacked by populism."