The short passage from Britain to France across the channel is one of the most important transport corridors in Europe. On Monday, hundreds of trucks backed up for miles, prompting concern that food and other time-sensitive cargo might end up rotting on the roadside. British supermarket chain Sainsbury's warned: “If nothing changes, we will start to see gaps over the coming days on lettuce, some salad leaves, cauliflowers, broccoli and citrus fruit – all of which are imported from the continent at this time of year.” LYNDA HALLINAN/Stuff Sainsbury's has warned shoppers their may be a shortfall of lettuce, cauliflowers, broccoli and citrus fruit for Christmas.