The growing Coalition row over wind farms saw a Liberal Democrat Cabinet minister take legal advice in a battle to remove official responsibilities from his Conservative deputy.
The fall out – one of the most serious Whitehall clashes since the Coalition was formed in May 2010 – involved Ed Davey, the Energy Secretary, appealing in vain to David Cameron over comments made by John Hayes, the Energy Minister, who is a firm opponent of onshore wind power.
Last night, a spokeswoman for the Department of Energy and Climate Change (DECC) admitted there were “some differences over some areas of policy” between the two.
This month. Mr Hayes defied his Lib Dem boss to insist no more wind farms beyond those already planned would be built. “Job done … end of story,” he said in a round of interviews.
A furious Mr Davey revealed this weekend that Mr Hayes’s remarks “against Coalition policy” had seen him attempt to have Mr Hayes stripped of his departmental responsibility for green energy policy.
He said he had consulted lawyers from his department over concerns that Mr Hayes’s continued presence in the job risked the department’s decisions being more at risk of judicial review at a time when the Government was trying to create “certainty” for energy investors.
Mr Davey said: “I left the decision with the Prime Minister. He has not written back formally, but it is fair to guess that he has come to the conclusion that renewable energy deployment could stay with John.”
The dispute appears to prevent anything resembling a working relationship between the two and underlines the stark differences of approach to a key policy between Liberal Democrats and most Tories.
Last week saw George Osborne, the Chancellor, strike a “deal” with Liberal Democrat ministers to pay for nuclear power stations and wind farms. Households and businesses will have to pay £7.6 billion a year by 2020 – with a typical energy bill set to rise by up to £178 annually.
Conservatives claimed the agreement saw Mr Osborne emerge victorious – because the Lib Dems originally wanted more taxpayer cash spent on green energy sources in the long term.
A Lib Dem demand for a target which would have forced Britain to get all its power from green sources by 2030 was thrown out, enraging green groups.
However, Mr Davey hit back with a claim that Mr Osborne has allowed him to give “advice” to the National Grid on the need to prioritise renewable energy. He said he would be sending the message “very clearly” that the Grid must increase the ratio of green energy consumed.
He also declared that shale gas reserves – a source being seized on by Conservatives as being likely to help meet Britain’s energy needs will not make a significant short-term contribution to the UK’s energy “mix”.
Mr Cameron ruffled Lib Dem feathers with changes at the Department of Energy and Climate Change (DECC) in September’s reshuffle. Responsibility for green energy was taken away from Charles Hendry, a Tory who supports wind farms, and handed to Mr Hayes.
Last month Mr Hayes said: “We can no longer have wind turbines imposed on communities. I can’t single-handedly build a new Jerusalem but I can protect our green and pleasant land.
“We have issued a call for evidence on wind. We need to understand communities’ genuine desires. We will form our policy in the future on the basis of that, not on a bourgeois Left article of faith.”
Mr Davey said: “When he made his statements against Coalition policy, I did think there was a question mark whether he should even continue to have responsibility for renewable energy deployment. I asked the legal department here whether there was a danger John had prejudiced himself because he had made these statements, and they said there was a danger.”
A DECC spokeswoman said: “The Coalition has agreed an ambitious package on energy policy that will put the UK on track to delivering its low-carbon objectives. John Hayes and Ed Davey are working together on this in the national interest.
“Yes, there are some differences over some areas of policy, but there is also a great deal of agreement.”