In medium saucepan, combine onion soup, tomato juice, and lemon juice. Heatslowly. When juice begins to simmer, add small portions of cheese and stirconstantly until melted. Continue to add cheese gradually, stirringconstantly, making sure each addition is melted. Remove to fondue pot orchafing dish or heated casserole. Spear cubes of bread, then dip and stirin fondue.