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The Energy and Climate Change Committee took evidence for its inquiry into Ofgem's review of the energy market.
Ofgem's review concluded that energy companies should offer simpler tariffs to help consumers compare prices.
The energy regulator launched its review in November 2010 after claims that suppliers were making excessive profits.
Earlier in the year, British Gas said operating profits had risen by 24% in 2010 to £742m.
Ofgem said that customers were "bamboozled" by a complex system of tariffs, which have increased from 180 to more than 300 since 2008.
However, industry body Energy UK said that the number of tariffs simply reflects consumer demand and competition within the industry.
The regulator also said that the "big six" suppliers should face more competition.
It believes these firms should be forced auction off up to 20% of the electricity they generate, to encourage the development of smaller companies.
The "big six" energy firms are British Gas, E.On Energy, EDF Energy, Npower, Scottish and Southern Energy and Scottish Power.
The committee questioned Ofgem chief executive Alistair Buchanan and his colleague Andrew Wright, before taking evidence from Energy Minister Charles Hendry.