The right hon. Gentleman put it correctly in his own blog, when he said:

"In an ideal world, we would all like to see the scheme that has the potential to provide the maximum amount of renewable energy and the least environmental impact in other ways".

But that might not be possible. We have looked at the costs, the environmental consequences, the benefits it would bring, the alternative schemes and the resulting diversion of capital, and we have decided that other tidal mechanisms would be better.