Mr Osborne is the leader of an increasingly influential faction within the Cabinet willing to sacrifice green policies if doing so is deemed helpful to economic growth.
The Chancellor's hostile stance has prompted much new scrutiny of the Government's environmental record – and an audit of its green policies by The Independent strongly suggests that David Cameron's boast of running "the greenest government ever" is now unsustainable. In a clear sign of the serious divisions over the environment at the highest levels of the Government, Mr Huhne, a Liberal Democrat, will reassert the importance of the Coalition's green policies – three weeks after the Chancellor aggressively downplayed them. Mr Huhne will turn Mr Osborne's own words against him. Whereas the Chancellor said at the Conservative Party conference that "We're not going to save the planet by putting our country out of business," Mr Huhne will say in a speech this morning: "We are not going to save our economy by turning our back on renewable energy."
And to Mr Osborne's complaint to the Tory faithful, in Manchester earlier this month, that "Britain makes up less than 2 per cent of the world's carbon emissions to China and America's 40 per cent," Mr Huhne will say: "Yes, the UK is only 2 per cent of global carbon emissions. But if we grasp the opportunity now, our businesses and economy can be much more than 2 per cent of the solution."
Mr Huhne's speech is an unusually forceful response to Mr Osborne's emergence as the clear leader of the anti-environmental faction in the Cabinet through his Manchester remarks. In them, the Chancellor surprised many people by openly attacking the jewel in the Government's environmental crown, its commitment to slash carbon emissions rapidly as part of its climate-change strategy; he hinted that the UK's CO2 reduction targets, now the toughest in the world, might be watered down in a review.
It is being noted that Mr Osborne's father-in-law, Lord Howell of Guildford – who as David Howell was a minister in Margaret Thatcher's government, and who has been given a job as a Foreign Office Minister in the current administration – has expressed climate-sceptic views in the past.
A mounting toll of anti-environmental measures, on everything from development of the countryside and eco-homes to illegal timber and oil-tanker safety, presents a picture of an administration which sees the environment as a distraction at best and at worst an obstacle to its core aims.
We highlight here 10 Government policies where the environment is unmistakably under direct attack, or being abandoned, or at least being sidelined, and, in several of them, Mr Osborne can be found at the heart of the matter. For example, the proposed major changes to the planning laws, which have prompted accusations that the Government wants to favour developers and "concrete over the countryside", come from Eric Pickles' Department for Communities and Local Government.
But their origin lies squarely in Mr Osborne's Treasury, and in the "Plan for Growth" which the Chancellor published at the Budget on 20 March this year, which announces: "The Government will introduce a powerful new presumption in favour of sustainable development – so that the default answer to development is 'Yes'."
In another widely remarked-on case, Mr Osborne has strongly limited the powers of the much-heralded Green Investment Bank, a centrepiece of the Tories' general election manifesto, by ensuring that it cannot borrow funds until the Government has completed its deficit-reduction plan in 2015.
Those observing government policy closely from the opposition benches firmly believe that the Prime Minister's "greenest" assertion now rings hollow.
"David Cameron's claim to be the 'greenest government' lies in tatters after just 18 months," said the shadow Energy and Climate Secretary, Caroline Flint.
"From neutering the Green Investment Bank, to scrapping zero-carbon homes and undermining solar panels on schools, the Government's old Tory ideas prevail at every turn. However green Chris Huhne tries to appear, we know that the true blues in Treasury undermine climate-change policies at every turn," Ms Flint said.
Mary Creagh, the shadow Environment Secretary, commented: "George Osborne's out-of-date 'go slow' on green issues has infected the entire Government, which is why they are even failing on their own coalition commitments."
Yet this perception is by no means simply party political. "Until Osborne spoke at the Conservative conference, the Coalition's quite good record on climate change had masked its poor record elsewhere," said Tom Burke, the environmental analyst and visiting professor at Imperial College, who was special adviser to three previous Conservative environment secretaries.
"That speech stripped away the climate cover, and revealed just how hollow the 'greenest government ever' pledge has been. The nasty party is back. Vote blue, get green, turns out to have been nothing more than a clever slogan."
Mr Cameron made his promise that his would be "the greenest Government ever" to civil servants in the Department of Energy and Climate Change, in a meeting which was widely reported, just after taking over as Prime Minister of the Coalition Government in May 2010.
It followed on from his own embrace of the environment after taking over as Tory leader in 2005 as a policy which could help to "decontaminate the brand" of Conservatism – with the party having long been seen as out of touch, especially with young people. Mr Cameron made a celebrated trip the climate-change-threatened Arctic to ram the point home.
From green back to blue: 10 anti-green Tory policies
Rural planning reforms
Proposed new planning rules would abolish the presumption (in place since 1947) that the ordinary countryside has value and will be protected. The default answer to development proposals will be Yes.
Eco-homes
The definition of "zero carbon" for new eco-homes has been watered down substantially by not counting carbon emissions arising from plug-in appliances (from cookers to TV sets) – up to half the household total.
Green Investment Bank
The Green Investment Bank, set up to fund major renewable energy projects, will not be allowed to borrow until 2015, greatly limiting its powers. Critics say it has been neutered.
Aggregates fund
The aggregates levy sustainability fund, which raised millions of pounds from sand and gravel and recycled it to nearly 200 green projects, has been wound up.
Gagging of agencies
Natural England (the wildlife watchdog), the Environment Agency and the Forestry Commission have all been told they are forbidden from policymaking, or commenting on policy.
Oil spilltugboats
Funding is being withdrawn for four ocean-going tugs, such as the Anglian Monarch, capable of towing oil tankers in distress.
Abolition of advisory panels
The Sustainable Development Commission and the Royal Commission on Environmental Pollution have simply been scrapped.
80mph speed limit
Raising the speed limit to 80mph will add more than 2 million tonnes a year to Britain's CO2 emissions, according to the Government's Climate Change Committee.
Illegal tropical timber
The Tory manifesto promised that the possession of illegally imported tropical timber would be a criminal offence. This promise has now been abandoned.
Forests sell-off
The Government decided to sell off the public forest estate, although there had been no mention of the idea in either the Conservative manifesto or the Coalition document. Public outrage stopped them.
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