Barbecued Pork Loin

1 (3 to 5 pound) pork loin
1 can tomato soup
1/3 cup chopped onion
1/3 cup chopped celery
1 clove garlic, minced
2 tablespoons brown sugar
2 tablespoons Worcestershire sauce
2 tablespoons lemon juice
2 teaspoons prepared mustard
4 drops Tabasco