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National Planning Policy Framework

I want to make some progress, and the hon. Lady intervened earlier. Let me say something about the definition of sustainability, which I know has attracted some interest. The definition that we have used is the one used by previous Governments. It is the Brundtland commission's definition, which has stood the test of time. It has been suggested that it is a high-level definition, so there should be a further elaboration of it. Hon. Members will know that planning policy statement 1, for example, contains the Brundtland definition in one paragraph and includes an extra 10 lines referring to the sustainable development strategy. That has been part of the previous document and some organisations and perhaps some Members have suggested that we should make reference to the current version of the sustainable development strategy, the 2005 document.