PAN wrote to Tesco, Wilko, Wickes, Sainsbury, The Range, Notcutts, Morrisons, Lidl, Home Retail Group, Dobbies, Co-op, Asda, Aldi and Amazon in 2015 "asking them to follow the example of German and Swiss retailers who have already voluntarily stopped selling glyphosate".
Mole said: "B&Q were the only ones that showed any interest. The rest just said it was approved so they would carry on selling it."
Last month, Waitrose said it had stopped selling Roundup, becoming the first big UK retailer to do so. But Mole said there was no sign of anyone else following suit. He said he was in the process of contacting the retailers again. Mole added that Waitrose probably still used glyphosate on its farmland.
Soil Association head of policy Emma Hockridge said Waitrose bread would have glyphosate traces in it. The Soil Association has been running a campaign on the issue.