In an exclusive interview with Channel 4 News, Energy Secretary Ed Davey urges the chancellor not to abandon his green strategy - and warns that some Tories seem content to retain their "toxic" image.
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In a wide-ranging interview with Channel 4 News's Political Editor Gary Gibbon as part of the programme's In Conversation With series, the environment secretary talked about life in coalition, his own background and his disabled son.
He urged the Chancellor George Osborne not to abandon his commitment to carbon credits. Mr Davey said: "The thing about the chancellor is, you've got to remember that he's going to be judged about how well he delivers growth, by his party, by the people.
"I think it's very important when the fourth carbon budget comes up that we proceed with that to show that this government across the coalition is committed to tackling climate change. I think if we don't proceed with the carbon budget that will be a very negative sign."
I would never let anyone write off my son. Ed Davey MP
On life in coalition with Conservative party colleagues, Mr Davey was frank: "I think the issue we have with our Conservative colleagues is that they are not all united around what is sometimes called the detoxification strategy. Some of them want to remain toxic."
But he added that he wanted the coalition to succeed: "I am being diplomatic. I think it's important to be diplomatic because I want the coalition to work."
And he was criticial of the Labour party who also negotiated with the Lib Dems after the last election: "I think the way they [Labour] often treated us when they were in government was frankly arrogant. They didn't appear to be into pluralist politics and I think that should be a lesson for us.
"If they are going to want to engage with our party they're going to have to show that they listen, and understand, our party and to be more credible on progressive politics they've got to understand pluralist politics. I think their level of arrogance and their unwillingness even to listen to their own side I think got them into an awful lot of trouble."
He also spoke about how his background and home life have affected his views on some current key political issues. Mr Davey's father died when he was four and he later cared for his mother when she was being treated for bone cancer.
He said: "She was in a lot of pain - bone cancer is extremely painful - and I used to administer her morphine, there was a treatment which involved giving her electric shocks to help with the pain.
"It was not a good time. It was very difficult for me and it's obviously influenced what I think about life and to take one practical example that's the need to support young carers."
He also talked about his son John who is disabled: "John is my joy. He's five in November, but he has a few difficulties. We thought it was cerebral palsy, but now we think it might be something else. He can't walk or talk but he can understand you... he's got a mean sense of humour...
"People write off cerebral palsy children because they can't speak, they think they are stupid. And I guess with many other conditions, where disabled people get written off because they can't speak. We must never let that happen. I would never let anyone write off my son."