Energy Secretary Chris Huhne will this week chair a summit of gas and electricity suppliers in a bid to cut prices.
Mr Huhne has invited bosses of smaller energy firms to tell him what steps are needed to break big companies' hold on the market.
He told customers: "Our energy market has been too cosy for too long. I'm calling a summit of independent energy suppliers so the small guys have an equal chance to bid for your business.
"We need more competition to keep bills down - it is madness that 99% of people get their energy from the 'Big Six'.
"Over the next decade we need double our normal energy investment to replace old power stations and keep the lights on.
"Doing nothing isn't an option - addiction to more foreign gas will put us at risk of oil and gas price shocks."
Mr Huhne has asked chiefs from firms including Ovo Energy, First Utility, Ecotricity, Co-op Energy and Good Energy to Thursday's meeting in London.
The summit comes just days before the Government unveils plans to revamp the electricity market.
Ministers hope the biggest shake-up in a generation will deliver more than £110 billion of investment ministers believe is needed over the next decade to upgrade the UK's creaking system and keep the lights on.
Mr Huhne added: "The current market simply can't deliver, so we need more companies and more competition to keep price rises as low as possible."
