ABSTRACT
If it is correct that Kleinwort Benson v Lincoln makes restitution generally available where a performance is based on a supposed void or non-existent obligation, the line of authority based upon Hobhouse J’s judgment in the Westdeutsche case will no longer be relied upon in such cases. The Lincoln model of restitution for mistake of law represents a much more secure basis for claims of this kind. As was argued in Chapter 5, however, the results will be no different. The focus is not on the performing party’s state of mind but on the validity and existence of the underlying obligation.1 In essence, this version of ‘absence of consideration’ amounts to an importation of the German Leistungskondiktion into English law. In this chapter, we will discuss the question whether ‘restitution for nullity’ can be defended on the basis of authority and principle. We will then consider the remaining scope of the Westdeutsche line of authority. The language of ‘absence of consideration’ is out there now. It is possible that it will not be possible to restrict it to cases to which German law would apply the Leistungskondiktion. There is a danger that the contagion will spread further. The result would be a general and as yet unprincipled general cause of action in unjustified enrichment. This danger will be addressed in the second part of this chapter.
