42In that regard, it must be clarified that, in circumstances such as those in question in the main proceedings, nothing precludes the national court from, inter alia, inviting the parties to negotiate with the aim of establishing the method for calculating the interest rate, provided that it sets out the framework for those negotiations and that those negotiations seek to establish an effective balance between the rights and obligations of the parties to the contract taking into account in particular the objective of consumer protection underlying Directive 93/13.