Energy Secretary Chris Huhne has described £66,000 as "a few thousand" as he defended his decision to challenge a court ruling over solar subsidies.
Mr Huhne was confronted in the Commons about his department's attempt to overturn a court judgment that ministers' axing of feed-in tariffs for solar power was unlawful.
However, he blamed his predecessor, current Labour leader Ed Miliband, for the "mess".
The Government's legal fight has so far cost taxpayers £66,000 - and Labour urged Mr Huhne to abandon the case before "wasting" any more cash.
North Tyneside MP Mary Glindon said: "How much more public money do you intend to waste fighting the court ruling?"
Speaking at Energy Questions in the Commons, Mr Huhne hit back: "Spending a few thousand pounds in order to save consumers £1.5 billion, which is what would have happened if we had left this case to run - the reality is that Labour introduced a scheme which was fundamentally flawed."
He added: "As with other issues we are putting Labour's mess right."
The Liberal Democrat Cabinet minister said the reduced subsidy would allow the Government to fund twice as many installations as the previous rate.
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.
Ministers believe the scheme was too generous and too expensive but on Wednesday three appeal judges unanimously upheld a High Court ruling that Mr Huhne lacks the power to introduce the controversial "retrospective" scheme.