“ Acts adopted in the framework of enhanced cooperation shall bind only participating Member States. They shall not be regarded as part of the acquis which has to be accepted by candidate States for accession to the Union. ”

“ The decision authorising enhanced cooperation shall be adopted by the Council as a last resort, when it has established that the objectives of such cooperation cannot be attained within a reasonable period by the Union as a whole, and provided that at least nine Member States participate in it. ”