The Government has lost a bid to appeal to the UK's highest court over its plans to cut subsidies for solar panels on homes.
In January three Court of Appeal judges unanimously upheld an earlier High Court ruling that the Energy Secretary lacks the power to introduce the controversial "retrospective" scheme.
After the decision by the appeal judges the then-energy secretary Chris Huhne announced that he would seek to appeal to the Supreme Court.
However today, the Supreme Court refused the Government permission to appeal, announcing that the application "does not raise an arguable point of law of general public importance which ought to be considered by the Supreme Court at this time".
The Government wants to reduce feed-in tariff subsidies (FITs) - payments made to households and communities that generate green electricity through solar panels - on any installations completed after December 12 last year.
High Court judge Mr Justice Mitting ruled before Christmas that it would be unlawful to implement plans to approve the cuts in April this year by referring back to the December 12 deadline.
The deadline fell 11 days before the end of a consultation period on the proposals.
Lawyers for the Government appealed and argued that Mr Justice Mitting had gone wrong in law and the Secretary of State possessed the necessary power to modify the tariff rate in the way he proposed under the 2008 Energy Act.
However appeal judges Lord Justice Lloyd, Lord Justice Moses and Lord Justice Richards disagreed.
In the lead judgment, Lord Justice Moses declared the Energy Secretary "plainly has no such power to make a modification with such a retrospective effect".
Parliament had never conferred such a power, he said.
The appeal court's unanimous decision was a victory for environmental campaigners Friends of the Earth (FoE) and two solar companies - Solarcentury and HomeSun - which said the plans to halve subsidies were creating "huge economic uncertainty".
Opponents have said that, if allowed, the proposals would put 29,000 jobs in the solar industry at risk.
They say projects have already been abandoned and jobs lost because of the uncertainty.
friends of the Earth's executive director Andy Atkins said: "This is the third court that's ruled that botched Government solar plans are illegal - a landmark decision which will prevent ministers causing industry chaos with similar subsidy cuts in future.
"The coalition must now get on with the urgent task of restoring confidence in UK solar power.
"The Government recently pledged a huge increase in solar by the end of the decade. It must now spell out how it is going to achieve this.
"Investing in clean British energy will create thousands of new jobs and help reduce our reliance on expensive fossil fuel imports."