Some of Europe's biggest trade partners fear a potential EU ban on glyphosate could hit exports of crops ranging from Australian wheat to Brazilian soybeans.

Just seven weeks before the license for the world's most common weedkiller runs out in Europe, agricultural powerhouses, including Argentina, Australia, Brazil, Canada and New Zealand, are pushing Brussels for answers over the fate of their exports to the EU.

Their chief concern: If the EU blocks its own farmers from using glyphosate, those same farmers could make it almost impossible, politically, for Europe to continue importing food grown using the herbicide. To avoid accusations of double standards, EU countries will be under massive pressure to restrict imported products containing glyphosate.

In technical terms, action against imports would be relatively straightforward. According to a 2005 regulation, a ban on glyphosate would open the door for the EU to revise down the permissible "tolerance" level of the chemical in food imports.

Argentina joined forces with other big exporters and is "following the development of the renewal for the authorization of glyphosate very closely, and is also taking some steps within its reach that could serve to ensure that the right decision is made," said Adrián Serra, head of the trade section at the Mission of Argentina to the European Union.

If glyphosate is no longer on the market after December 15, the mechanics of limiting imports could take two paths.

A glyphosate ban would contradict scientific findings from the European Food Safety Authority and the European Chemicals Agency, both of which deemed it to be safe, Serra said. These conclusions differ from the World Health Organization’s International Agency for Research on Cancer, which deemed glyphosate was “probably carcinogenic.”

Argentine Agriculture Minister Ricardo Buryaile expressed his concern about the impact on soybean exports in a letter to European Commissioner for Agriculture Phil Hogan and Commissioner for Health Vytenis Andriukaitis, according to two officials who saw the letter.

These worries about the impact on trade flows stemming from a ban on glyphosate were raised earlier this year in the World Trade Organization's Committee on Sanitary and Phytosanitary Measures. During a meeting March 22 and 23, Argentina told members of the committee that there were "concerns regarding the immediate impact on trade of agricultural products if the authorization [for glyphosate] was not further renewed."

Australia, Brazil, Canada, Chile and New Zealand echoed the concerns of Argentina, according to minutes from the meeting.

If glyphosate is no longer on the market after December 15, the mechanics of limiting imports could take two paths.

If the ban is introduced because of health concerns, the EU must inform the WTO it is reducing its maximum residue levels for glyphosate to 0.01 milligrams per kilogram. That would be significantly below the 20 milligrams per kilogram limit now allowed for soy imports from Brazil, for example.

Should the ban be implemented for reasons other than health, the Commission can introduce a so-called import tolerance procedure, which allows for a higher maximum residue level than 0.01 milligrams.

Negotiations could, however, lead to an effective import ban.

Canada's grains industry argues that Italy is looking to leap on a glyphosate ban to limit imports of Canadian durum wheat, widely used in pasta making.

Cam Dahl, president of Cereals Canada, accused Italy of protectionism. “We’re the largest exporter into Italy … From my perspective it’s a very active campaign to denigrate the quality and safety of Canadian durum — of course that is not based on science.”

Despite the rapidly approaching deadline to decide on whether to renew glyphosate's license, there is little sign of consensus. The Commission proposed a five-year renewal, but major member countries oppose this. Germany is trying to marshal support for a three-year extension. France and Belgium want the chemical to be phased out.

Countries will try again to strike a deal on November 9, a little more than a month before glyphosate's EU license expires on December 15.

Should there be no break in the impasse, it will fall to the Commission to decide.

Emmet Livingstone contributed reporting.