One way in which it could do this is to stress the likelihood of cheaper gas cutting household gas and electricity bills. The more shale gas Britain produces, the less it will have to import, enhancing energy security. And the more gas replaces coal in power generation, the lower our carbon emissions.

That would seem a reasonable solution to the so-called "energy trilemma" beloved of policy-makers around the world: how to reconcile the competing requirements of affordability, security and sustainability.

There are signs that elements on the Right of British politics are waking up to this. UKIP wants to scrap all renewable subsidies and promote fracking for shale gas. The Tories are divided, with the modernising social liberals clinging to current policies. But in October, Owen Paterson, recently sacked as Environment Secretary, told the Global Warming Policy Foundation:

Our current policy will cost £1,300 billion up to 2050. It fails to meet the very emissions targets it is designed to meet. And it fails to provide the UK's energy requirements. Current energy policy is a slave to flawed climate action. It neither reduces emissions sufficiently nor provides the energy we need as a country. I call for a robust, common-sense energy policy that would encourage the market to choose affordable technologies to reduce emissions.

This was an important speech, under-reported by the mainstream media. Whether it represents a turning of the tide within the Conservatives must be open to doubt so long as David Cameron heads the party. His instincts are always to tack towards the centre and, as far as practical, towards the left of British public opinion.

But Mr Cameron and his advisers should consider that Ed Miliband's cynical promise to freeze household energy prices from 2015 risks not only further delay to vital infrastructure investment but may also presage renationalisation of parts of our energy industries. For the first time in a generation, the Tories have the opportunity to open up a real and principled gap between themselves and their opponents, offering a future of self-reliance, cheaper energy, lower carbon emissions and the end of a heedless dash towards inefficient renewables.
To pull that off, the Tories would have to bind themselves to a new moral imperative, this time one of their own creation. This is unlikely in the time remaining. But any Englishmen who still read Conrad may consider that for all the striving and suffering in Nostromo, the Sulaco silver all ended up at the bottom of the sea.