Neil Patel from AB News in South Byfleet, Essex, drew applause from other retailers when he told representatives of Mail Newspapers: "You and the other publishers have been taking the mickey out of us independents for years."
Neil said: "I start work at 4am and earn £3 an hour packing inserts for you - that's less than the minimum wage. Meanwhile, the nearby Co-op gets its copies delivered in polybags."
Others complained that they were unable to benefit from The Mail's promotions because they could not get sufficient supplies. "All the copies are going to Tesco," one said.
Mail Newspapers' Keith Godfrey assured retailers the company would look into their problems. "Independents are the lifeblood of The Mail," he said.