Juncker has responded in a letter to MEPs, following a letter from some MEPs in March asking him to "critically revise the validity" of industry-funded research that featured in glyphosate safety reviews, conducted by the European Food Safety Authority and European Chemical Agency.
Juncker replied, in a response obtained by Politico: "There is no reason to doubt the scientific evaluations and the conclusions on glyphosate made by the European Union."
The International Agency for Research on Cancer has previously said glyphosate is a potential cancer hazard. However over the past two years the US Environmental Protection Agency, European Food Safety Authority, UN/World Health Organization, German Federal Institute for Occupational Safety & Health to the European Chemicals Agency as well as New Zealand's Environmental Protection Authority have all found that glyphosate poses no cancer risk.
Juncker wrote: "I would like to recall that the Commission has followed a very cautious approach related to glyphosate. In 2016, it decided to extend the approval period for the substance for the period necessary to enable ECHA to evaluate the content. This decision was taken despite lack of information from the Member States. On the other hand, the European Parliament took a clear position and suggested in the Resolution it adopted in April 2016 that the Commission shall grant a renewal.
He cited Regulation (EC) No 1107/2009 and the EC's approach to regulating products.
Juncker added: "In the light of the thorough examination of all the information available by the European Food Safety Authority and the European Chemicals Agency, there are no reasons to question the scientific assessments and conclusions on the glyphosate in the European Union.
"Following the presentation of the final opinion of the European Chemical Commission, the Commission services will resume discussions with the Member States with regard to the possible renewal of the authorization due to the legal obligation to take a decision within six months of the receipt of the
Notice, or by the end of 2017 - at the latest.
"I believe that the EU regulatory system is robust and ensures protection for humans and the environment."