change and global warming. We are likely to respond to the royal commission at the same time that we publish the energy White Paper.

The energy review was published on 14 February. Having chaired the advisory group that oversaw that process, I should like to record my appreciation to the members of the team led by Nick Hartley, which produced an excellent report to time. The PIU report was always going to be a report to the Government, rather than of the Government. When the Prime Minister welcomed the review on behalf of the Government, he said that he hoped that it would start a thorough debate. The consultation that we launched on 14 May in the run-up to the White Paper initiated the next stage of that debate.

WeDown a track through beech woods so thick you must turn on your car headlights lies a secret meadow, full of flowers. Mauve scabious and darker purple knapweed wave their heads in the aftermath of a summer thunderstorm. "If anyone asks, we're looking at ants and flowers," instructs David Simcox, abruptly swinging his walking boot into the flowery turf. This furtive act of apparent vandalism is one small step in what may be the most complex and successful conservation project in the country: the reintroduction of the once-extinct large blue butterfly.

This insect, which baffled conservationists for more than a century because of its strange and wonderful life cycle, became extinct in Britain in 1979. In the following decade, two scientists brought it back to life: Jeremy Thomas, professor