In quotes: Reaction to Miliband's energy price pledge
Ed Miliband has told the Labour conference that household and business energy prices will be frozen for 20 months if the party wins the next general election.
Here is a round-up of political and business reaction to the announcement.
Alistair Phillips-Davies, Scottish and Southern Energy chief executive
"Instead of price freezes which will lead to unsustainable loss-making retail businesses, the Labour Party should put policy costs into general taxation, taking them off energy bills.
"This would wipe £110 off the average person's bill and shift the cost away from those who can't afford to pay and on to those who can."
Paul Massara, RWE Npower chief executive
"It's very easy for politicians to come up with simple-sounding solutions to difficult problems.
"But in reality, there are three main factors that influence prices: fixing inefficient housing stock: the investment required to replace the UK's energy infrastructure and the cost of buying energy on the global market.
"If the Labour Party can commit to reducing policy costs on household energy bills, stopping the smart meter roll-out, preventing commodity cost increases and accept that there won't be any investment in new power stations and infrastructure, then we could freeze our prices.
"But will this make things better for Britain?"
Sir Roger Carr, Centrica chairman
"If prices were to be controlled against a background of rising costs it would simply not be economically viable for Centrica, or indeed any other energy supplier, to continue to operate and far less to meet the sizeable investment challenge that the industry is facing."
Angela Knight, Energy UK
"Disbanding Ofgem to create Ofgem II is posturing to no purpose. Energy companies have already simplified the tariffs they offer.
"The energy companies are already regulated and fully open about what they make, what they pay and the amount they are reinvesting.
"Today's announcement is not the adult debate the industry has long been calling for and that customers deserve."
"Under current arrangements prices are determined by companies competing in the market.
"It is for government to set the policy framework and to decide whether this continues to be the case.
"In this context, Ofgem is committed to making the market work well for consumers and is introducing the most radical set of reforms since competition began to make the market simpler, clearer and fairer."
Richard Lloyd, Which? executive director
"Ed Miliband's promise to fix the broken energy market and freeze prices will give hope to the millions worrying about how they can afford to heat their homes.
"We now look forward to seeing the detail of how this will work.
"Wholesale costs are the biggest part of the eye-watering rises to energy bills that people have faced over the last ten years. Making the wholesale market competitive by separating energy generation from supply is essential to help keep prices in check."
John Cridland, CBI director general
"Businesses will view the proposals on tax and energy as a setback for Labour's pro-enterprise credentials.
"Rising energy bills are tough on families and businesses. But the proposed energy price freeze will deter much-needed investment and is at odds with Labour's pledge to decarbonise the economy and create a million green jobs.
"The main reasons that bills are going up is the combination of rising wholesale prices, the cost of policies needed to keep the lights on and the move to a low-carbon economy."
Ed Davey, Secretary of State for Energy and Climate Change
"Everyone wants to help with the cost of rising bills, which is why Liberal Democrats have cut income tax by £700 for working people.
"But Labour's plan is a promise that won't work.
"When they tried to fix prices in California it resulted in an electricity crisis and widespread blackouts. We can't risk the lights going out here too.
"Fixing prices in this way risks blackouts, jeopardises jobs and puts investment in clean, green technology in doubt."
Grant Shapps, Conservative Party co-chairman
"Labour are committing to a de-carbonisation tariff which would mean that people have to pay more for their electricity. So everything he is promising to take off, they are promising to put on.
"It is a sleight of hand and, I have to say, pretty disingenuous.
"What we do want to make sure is that consumers get the best deal - it is far too confusing at the moment.
"That is why we are already legislating to make sure everybody is put on the lowest tariff - some real help now rather than waiting for it."