Who runs Britain’s energy policy? We have a Department of Energy and Climate Change – you might think from their name that they do. Or perhaps it’s Chancellor George Osborne’s Treasury that calls the shots? Now you’re getting warmer.

This week's announcement by the Energy Secretary, Ed Davey, that he had secured only a 10 per cent cut in wind power funding, was heavily spun as a victory for the Lib Dem-run department. Given that the Treasury had been demanding 25 per cent cuts, this seemed a victory indeed – but one with a huge hidden cost. Because, as payment for this victory, Davey has been forced to quietly concede to another of the Treasury’s demands: a commitment to decades more of dirty and expensive gas.

We know this to be the Chancellor’s wishes, because on Monday someone leaked a letter – effectively a ransom note – that he had sent to Davey outlining his position. In it, Osborne demanded that the Energy Secretary issue “a statement which gives a clear, strong signal that we regard unabated gas as able to play a core part of our electricity generation to at least 2030 – not just providing back-up for wind plant”.

Acceding to this outrageous demand would mean seriously jeopardising the UK’s fight against climate change. As the Government’s independent advisors, the Committee on Climate Change, stated in response: "This would all lead to a second dash for gas. This would be incompatible with the government's climate change goals."

But on Wednesday, DECC dutifully trotted out a press release stating that “the Government… is today confirming that it sees gas continuing to play an important part in the energy mix well into and beyond 2030”. Some victory.

The exchange has also highlighted the hypocrisy of the Treasury in its assessment of what merits public subsidy, and what must go without.

Osborne stated in his letter to Davey: “While your proposals [on renewables funding] achieve some savings we will still be paying more than £500m more to support renewable generation in 2013-14 than we collectively agreed was affordable”. No-one disputes that as technology costs come down, public funding for renewables should decline; the renewables industry itself was offering up 10 per cent cuts.

But wait; what’s this? On Wednesday, as DECC announced its cuts to renewables funding, the Treasury simultaneously unveiled £500m of tax breaks for offshore gas drilling. What’s unaffordable to spend on clean energy suddenly becomes eminently affordable to spend on drilling up the dirty stuff.

Enough is enough. The Chancellor must be prevented from undermining the UK’s green economy – as the CBI recently stated, it’s one of the few parts of the economy still growing. A high-carbon energy system will lock the UK in to a high-cost as well as high-polluting future. So in whose interests is the Chancellor acting?

It’s now up to David Cameron and Nick Clegg to back their Energy Minister over the Chancellor. They should insist that the Energy Bill includes a target to decarbonise the UK’s electricity system by 2030 and unlocks support for clean British energy. The alternative energy strategy that George Osborne would have us follow is a dirty and dangerous dead end.

Guy Shrubsole is an Energy Campaigner at Friends of the Earth. For more information on Friends of the Earth’s Clean British Energy campaign: www.cleanbritishenergy.co.uk