Tesco's commercial and marketing director, who takes up the top UK role in March, told delegates that only by working together could the industry solve big problems such as the environment and obesity.
He revealed that he had recently written to Tesco's top 1,000 suppliers asking them for their help on reducing carbon emissions.
"There is a suspicion about being set targets and what that would mean if you miss them," he said. "I am asking people to join the 30% less club. It does not mean we are going to measure whether you did or didn't achieve."
Neither did it mean Tesco was about to ease up on negotiations, he warned. "Together we've delivered, but when I say together, I'm not trying to conjure up a cosy relationship. The hallmark of our industry is competition. I believe in commercial tension between retailers and suppliers. I think it's positive and healthy."
However, one supplier said that the fact Brasher had even mentioned collaboration was significant. "It's finally reaching out and realising it can't save the world alone," he said.