Bring a pot of water to boil, add carrots and boil until the carrots are just tender, approximately 10 minutes. Drain well.
In a mixing bowl combine the celery, green pepper, carrots and onion.
Bring tomato soup, oil, vinegar and sugar to a boil. Stir well. Remove the mixture from the heat and let cool, 10 to 15 minutes. Pour the mixture over the vegetables, mix until all of the vegetables are coated. Marinate this salad overnight before serving.