It is an archetypal sunny Monday morning in Los Angeles and Tim Mason is standing outside the Eagle Rock Fresh & Easy store in his "lucky" green-striped shirt, which he fishes out of the wardrobe every time he cuts the ribbon on a new neighbourhood shop.

Today there is not a store opening; there has not been one of those for the past three months after Mr Mason, chief executive of Tesco US, pressed the pause button on the 200-store roll-out to "smooth out any wrinkles".