The hon. Gentleman is right, particularly in his last point. The Prime Minister said that sustainability was at the heart of the Labour party programme. The heart of the Bill is the part that we are seeking to amend, and sustainability should be included in that. For that, it must be defined. It is better to have a poor definition that gives at least some indication than merely to use words with no definition and to tell the House that everything will be done by regulation afterwards. I shall say something in a moment about regulation, with particular reference to the new clause.