Allan said there had been "very robust discussions" between Tesco and a number of suppliers, and referenced last year's spat with U.S. food giant Kraft HeinzKHC.O. Official inflation data for December published last week showed food prices 16.8% higher than a year earlier, the sharpest increase since September 1977, led by eggs, milk and cheese. "It was almost like he was living in a parallel universe," she told BBC radio on Monday, noting farmers and growers were facing unprecedented hikes in production costs.