Heat the oil in a large saucepan. Add the onion, celery and garlic and fry until the vegetables are soft.

Stir in the seasoning and herbs and cook for a further 1 minute. Stir in the tomatoes and cook for 5 minutes.

Pour over the wine and water and bring to the boil. Reduce the heat to low and simmer the mixture for 10 minutes, or until the tomatoes become pulpy.

Add the mussels and cook over moderate heat, shaking the pan occasionally, for about 10 minutes, or until the shells open. (Discard any shells that do not open.) Transfer the mussels from the pan and remove and discard the top shell.

Transfer the mussels to a large, warmed tureen and keep hot.

Strain the soup into a bowl, pressing on the vegetables with the back of a wooden spoon to extract all the juice. Return the strained soup to the pan and bring to the boil. Cook for 2 minutes, then pour over the mussels. Sprinkle over the parsley and serve at once.