Representatives from the Big Six were recently called before a panel of MPs, being asked to justify their recent round of price rises.
On the 29th October, bosses from all of the largest energy suppliers were questioned on why they have raised their prices for the third successive winter.
They all say rising wholesale costs, increased transmission charges, and extra green taxes are to blame.
The representatives of the energy companies were brought before the Energy and Climate Change Comittee, alongside Andrew Wright, chief executive of Ofgem.
During the meeting, Tony Cocker, chief executive of E.ON, said that “a very thorough Competition Commission inquiry” was needed. This had already been suggested by EDF earlier that month.
Ofgem say that a review is due out in Spring 2014.
Centrica however, owner of British Gas said they “believe it unnecessary as the market is competitive”.