Translate the following English sentence to French:
"Having said this, it is an ambitious and difficult project, because, as you have mentioned, it requires a change to the Treaty and to the constitutions of at least four or six Member States."
Ceci dit, il s' agit d' un projet aussi ambitieux que difficile, car, comme vous l' avez dit, cela suppose une modification du Traité et des constitutions d' au moins quatre ou six États membres.