The government has been dropping broad hints of its new enthusiasm for privately funded nuclear power plants. The latest one was implicit in last week's announcement of unexpectedly tough caps on carbon dioxide emissions from 2008-12.

The government is steadily restricting the supply of tradeable permits to emit carbon. This is the most cost-effective way of reaching any given emissions target because it means that those who can easily clean up their act will do so while those who are producing valuable products will instead buy permits.