Mr & Mrs Greener: But are the Camerons what they seem?

The windmill has been taken down and he is cross. "It was a sweet little thing," says David Cameron within moments of opening the front door of his new eco-home in west London, "a lot smaller than a television aerial".

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The mini-turbine was meant to be spinning by now, generating a trickle of electricity - and declaring the credentials of the leader of the new earth-friendly Conservatives. It was going to be a whirring banner for his environmentalism, the symbol of his personal righteousness in doing things like attack Tony Blair for making a carbon-guzzling "pop star" farewell tour of the world.

The plan went wrong, just as his abandonment of grammar schools threatens to go wrong. Some senior Tories are outraged that he thinks no more grammars should be built (a position he modified when their ire became clear). Former party deputy chairman Bernard Jenkin has described this as "the first skid mark" of the Cameron era. But we are talking before all that, in the days preceding a family holiday in Crete that has taken him (with characteristic good fortune) out of the country during the worst week of his leadership. So it is not the wrath of Tory grandees that is on his mind but that of his local council.

"Somebody complained and it had to come down," Cameron says of the windmill in a mock sulk, making coffee in the open-plan kitchen and living room at the back of his house. The whole of one wall is made of glass, allowing early morning light to pour in from the garden. That's where the rainwater harvesting tank is buried.

His children are not even out of bed yet, but Cameron is dressed, in French blue, hair slicked back. I am the first interviewer to see him in the new-look house. It offers a tempting metaphor for his attempts to reinvent the Tories with the slogan "vote blue, get green".

From the outside it looks like other solid Edwardian terraced homes in his North Kensington street - apart from four alarmingly shiny metal bins. Inside, the white walls smell strongly of paint; pictures are propped up yet to be hung, including a poster for the Ingrid Bergman film Stromboli. All appears stylish and modern, just as the well-tailored 40-year-old Etonian would like us to see him. There are signs of humanity - his wife Samantha's party shoes lying on their side in the centre of a white rug - that even the controversial new party head of communications Andy Coulson (former editor of the News of the World) would find it hard to beat. The house is also stuffed with eco tricks - at least one of which does not work.

"The windmill is sitting in my builder's garden," he says. "It was up for about a week." He had planning permission for it to go on one side of the chimney but the roof wouldn't hold it; so the builders put it on the other side - where there was no permission. "The architect advised me to take it down or be in breach, which wouldn't be right."

The windmill wasn't very good anyway, he admits. "It's not that windy. But for a couple of days it was generating some electricity. We will apply again. We're still in the learning phase."

Cameron says that a lot. He takes credit for greening his party and putting the environment at the centre of the political agenda since he became Tory leader in 2005. "I believe there would not be a climate change Bill about to go into Parliament if it wasn't for us." Talking about what the Camerons do as a family supports that position. But it is also asking for trouble.

Some of his eco-failures and compromises have become infamous, others will only be revealed as we talk. But as we run through the details, from organic vegetables and solar panels to the 90-mile flight he took in a private jet, he keeps repeating that his family is just like many others. "We're all learning."

Talking about it too. His rivals have been reluctant to do so until now, but were prepared to tell this newspaper what they do. Menzies Campbell, leader of the Liberal Democrats, uses energy-saving lightbulbs and is having his car converted to run off LPG. Gordon Brown, Labour leader elect, has solar panels and a compost heap, takes the Tube "when he can" and has spent his last three holidays in Scotland. Both men insist they recycle, insulate their homes and offset their official travel. A source close to Brown said, with irony: "David Cameron is clearly a model of how to live - and never misses an opportunity to tell us about it."

Brown and Cameron have both had to face challenges at home. David and Samantha's son Ivan, five, has epilepsy and cerebral palsy and needs round-the-clock care - perhaps the main reason for rebuilding the house - to provide him with the right facilities. They have two other children, Nancy, three, who pads downstairs as we talk and finds her father's lap; and Elwen, one, brought down by his mother to suck milk from a bottle on the sofa.

Elwen's nappies are biodegradable; the ones they use for Ivan, who will probably never walk or talk, are not - as a tabloid found out when it went through his bins. "Ridiculous," says Cameron. "They don't do biodegradable nappies for five-year-olds."

Seeing a copy of The Independent with the eco-home of the future he jabs a finger at solar panels and water heating pipes saying, "I've got that, and that." The same goes for an underground tank that stores rain to use in the house, and cavity wall insulation. "The unromantic things make much the most improvement."

What hasn't he got? A green cone, the pit and composter contraption leading Tories were urged to adopt. "At my constituency home in Oxfordshire the water table is quite high so the hole just kept filling up with water."

He still cycles to Westminster and back at least once a week, and his office insists a car doesn't follow with his shoes and papers as it used to.

We're heading for his constituency now, in the Lexus GS450 hybrid provided by his party. The Government offered him a greener Prius but "you can't sign letters: it has terrible suspension." He's not happy with the Lexus though. "There are other cars with lower emissions."

Asked about recycling he recites the intimate details of the orange bag scheme in London and the black boxes at his constituency home in Witney, then confesses again. "Like any family, we often sometimes struggle with the rubbish. We have to encourage people to take the steps they can in their own lives. This shouldn't be some hair-shirted, painful process."

They break the law in Witney, apparently. "My neighbour keeps pigs. We feed them our vegetable scraps. Illegally." He grows vegetables in the garden there. "I have got broad beans, potatoes and cabbages on the go. I've won prizes at my village show."

How on earth does he find time? "I have someone who helps cut the grass and stuff," he says reluctantly. So they're the gardener's vegetables, not his? "No, because... last year I pretty much did the lot myself." This year has been busier.

He wears Worn Again trainers made from recycled materials - but in April it emerged that the materials were shipped from Britain to China and back. The makers say they pay for carbon offsetting.

Flying embarrassed David Cameron in January when he used a private jet to make a trip from Oxford to Hereford. "It shows he believes there's one rule for him and his Tory friends and another for the rest of us," said a Labour MP. Ivan was cited in his defence: the businessman who sent the jet was helping design a new wheelchair. "I had to get back that afternoon to do some interviews about a very important issue and that was the way to do it," says Cameron. "So ... you know, look, you get criticised. That's life. You just have to take it."

Helicopters and planes are a big part of his life. "I don't hide that from anybody. As leader of a political party you have to campaign right around the country to very tight schedules, it's important you are back for things that matter in Parliament and that you try to keep your family together." He sounds agitated, for the first time. "I carbon offset all the flights."

Are family flights offset too? "Yes." In support of the same projects? "Yes. I can't remember which at the moment." The answer detailed by an aide later, is that they offset "all official travel and as much personal travel as we can" including all flights through Climate Care, whose projects include wind turbines in India.

Is his environmentalism for real? Labour points out that Tories have voted against windfarms and renewables as well as the climate change levy. Cameron has called for "a massive roadbuilding programme" but he remains unapologetic about that, saying the economy needs it.

Politically, he says his inspiration was a Margaret Thatcher speech on climate change in 1988, when she was Prime Minister and he was a junior Tory researcher. "She made it a primary subject," he says. Not so primary that the Conservatives felt they had to do much about it before 2005?

"That's a bit unfair, if you look at the record of John Gummer as Environment secretary, or Michael Howard signing the forerunner to Kyoto."

Personally, when did he find himself on the green road to Damascus? "I don't really believe in Damascene moments," he says, and talks about his upbringing in rural Berkshire, helping his mother keep sheep. He learned to castrate a ram with pliers. "Being brought up in the country helps you understand the connections between agriculture, landscape and environment."

The year 2001 was significant. Friends say Ivan's birth gave him the courage to take political risks. Cameron became an MP and started growing veg. Steve Hilton, his closest adviser, voted Green that year. By the time Cameron became leader four years later the pair had decided green issues were a perfect way to demonstrate he was a new, modern kind of Tory.

He flew to Svalbard in Norway. "The trip made a big impact on me," says Cameron. "Talking to people who have been studying melting glaciers for 20 years, proper scientists... it was possible to bring up all the nagging doubts and worries, the stuff you have read from the sceptics, and hear their responses." That was months after his election though, suggesting his environmentalism was tactical at first, surely? "[The trip] was very good confirmation of what I already believed," he insists.

He trusts his wife's instincts - and as we talk it emerges that Samantha was the true believer. "Funnily enough, she has always been very keen on these issues," he says, forgetting for a moment that Samantha's politics are not usually discussed. "She's been... erm... for a long time she was a member of Greenpeace, actually. The magazine used to flop through our door."

So she convinced him? "Yes," he says, suddenly more cautious. "I think that's probably true." Is Samantha still a member of Greenpeace? "I don't know. You'll have to ask her." For all his eagerness to be seen as green, Cameron is protective of his wife. So Dave the Eco-warrior uses self-deprecation as his armour once more: "I'd say again, we're both imperfect environmentalists," he says, smiling. "You'll find lots of holes."

Further browsing: David Cameron offsets his flights at climatecare.org

Eco Record: How green intentions become policy

Environmental accounts of the four major political parties:

The Labour Party

One of Gordon Brown's first budgets introduced a tax on landfill to encourage recycling. Soon afterwards he gave tax incentives for green cars and green homes. Labour introduced the climate change levy and pumped cash into home insulation schemes. Tony Blair has led efforts to build an international consensus on climate change and has been instrumental in bringing the United States on board. The Prime Minister has been sharply criticised for allowing conglomerates to bring genetically modified crops to the UK and for backing nuclear power without resolving the issue of what to do with radioactive waste. The party has been criticised for building more roads.

The Conservative Party

David Cameron may have pushed green issues up the political agenda but his party's record does not match his rhetoric. His head of policy, Oliver Letwin, led objections to a recycling plant in Poundbury, Prince Charles's model village. Tory MPs have tried to block wind farms in their constituencies. Tories have also opposed recycling schemes and road pricing. The Tories opposed the climate change levy and the utilities Bill, which requires power companies to invest in renewables. They have backed road expansion schemes. David Cameron is however committed to emissions targets. The Tories have opposed GM food and are active in protecting the countryside.

The Liberal Democrats

The Liberal Democrats had a comprehensive programme to protect the environment long before it was fashionable. MPs and their staff use eco-kettles and green taxi firms and for six years their headquarters has been using renewable power. Their manifesto to cut carbon includes increasing green taxes, raising vehicle excise duty on polluting cars, and making sure duty on fuel keeps track with inflation. They want reform of air travel, with an emissions charge per flight. They want strict standards for new housing, to cut emissions substantially without nuclear power. The party has been calling for more ambitious international targets on reducing greenhouse gases.

The Green Party

Greens want UK carbon emissions cut by 90 per cent by 2030. To do this they would halt airport expansion and double the climate change levy. They would tax aviation fuel, charge air passengers £100 to fly and scrap road building. VAT would be replaced with a green tax. Packaging would be taxed. The import of toxic and radioactive waste would be banned. There would be a moratorium on GM crops. The railways would be renationalised and expanded.

THE GREEN TEST

Gordon Brown

Good

He has solar panels on his roof and a compost heap. He spent the last three summer holidays in Scotland. He keeps the heating down, both in his office and his homes and recycles. Mr Brown uses low energy light-bulbs and offsets all his flight.

Bad

Drives a gas-guzzling four by four, for, his office insists, security reasons. He hasn't been vocal on green issues, and some environmentalists doubt his commitment. Seen by some as too keen on nuclear power, and not concerned enough about nuclear waste. Regarded as pro-GM food.

Result: Greener than he is given credit for

David Cameron

Good

He lives in a state-of-the-art eco-house, has an organic vegetable patch, feeds his kitchen waste to his neighbour's pigs and recycles papers, cans and bottles. He uses bio-degradable nappies for his youngest son. He cycles to Westminster at least once a week.

Bad

He was caught being followed on his bike by a car carrying his shoes and papers. His Lexus emits more carbon than the top 10 selling cars in the UK. His recycled trainers were made in a Chinese factory criticised for poor conditions. His wind turbine was removed due to planning problems.

Result: Has raised the profile of green issues

Sir Menzies Campbell

Good

He has loaned his beloved Jaguar to a museum and uses a less polluting vehicle which is being converted to run on liquid petroleum gas. He and his wife often holiday in Scotland on the Island of Tiree. He takes the train when possible and flights are offset. He drinks Fairtrade coffee in the office.

Bad

Not as green as some of his colleagues who use eco-kettles, have fought long battles against GM crops and have windmills on their roofs. Sir Menzies has been more concerned with foreign affairs and has not yet taken radical steps to reduce his personal carbon footprint.

Result: Not a natural eco-warrior