Chris Huhne has vowed to get consumers "the best possible deal" after a wave of price rises from the big six energy companies.
In an upbeat keynote speech to a packed hall at the Liberal Democrat conference, Huhne said the government would "get tough" with energy companies and tackle fuel poverty.
"It’s not fair that big energy companies can push their prices up for the vast majority of their consumers – who do not switch – while introducing cut-throat offers for new customers that stop small firms entering the market. That looks to me like predatory pricing. It must and will stop."
And he said energy regulator Ofgem would crackdown on predatory pricing by energy firms. NPower boss Volker Beckers immeditately kicked back, saying energy policy was becoming a "political football".
Huhne highlighted the economic opportunities in the low carbon industry could help provide jobs, promising ". It is our route to recovery. Green business is good business."
The energy secretary laughed off his unpopularity with Conservatives, telling delegates: "It’s been nip and tuck between Vince and me in recent months to win an unpopularity poll – that’s on ConservativeHome among Tory activists.
"So as we assert Lib Dem values within government, we must be doing something right – or is it Left?"
And his digs at the Labour party's lack of action were applauded by delegates.
The former MEP also asserted the coalition's commitment to staying in the European Union, and trading with European countries.
"We will not, as Liberal Democrats in government, weaken the ties that deliver our national interest through Europe."
In a further swipe at right-wing Tory MPs he said "we need no Tea Party Tendency in Britain", instead highlighting the importance of cooperation between coalition partners.
"If you fail to compromise, if you fail to seek the common ground that unites us, if you insist that only you have the answers, if you keep beating the anti-European drum, if you slaver over tax cuts for the rich, then you will put in peril the most crucial achievement of this Government.
"You will wreck the nation’s economy and common purpose."
Delegates gave Huhne a standing ovation after the speech and consumer groups have welcomed the promised action on bills, with Richard Lloyd, executive director at Which?, saying the government action on bills was "overdue but welcome":
“With many people facing price hikes of 10% to 20% this winter, Government action on rocketing energy bills will be overdue but welcome. For the millions struggling in fuel poverty, help can’t come soon enough this winter.
“Giving people information on their bills about cheaper tariffs is a step towards helping people to manage spiralling energy costs. However, when 60% of domestic energy customers never switch, the Government and Ofgem must now take action to inject genuine competition into the energy market. Serious questions must be asked about whether the major suppliers’ customer bases will need to be broken up in order to achieve a competitive market.”
But Labour shadow energy secretary Meg Hillier said families could not be expected to take Huhne's speech seriously.
"Only last week Chris Huhne was criticising consumers for not switching supplier.
"He is tinkering while people face a cold winter shivering under blankets. His own plans to reform the energy market do nothing of the sort and will exclude many potential new entrants.
"Labour called for more competition in the market months ago and for a competition commission enquiry. Chris Huhne is fiddling with an already broken system. Labour is calling for radical reform.
"Chris Huhne's failure to take on the energy companies is yet another example of how this Tory-led Government is refusing to tackle the irresponsible behaviour at the top, while hard working families suffer."