A number of UK energy suppliers have protested against the possibility of an industry wide inquiry - claiming the number of operators is the highest it has been in more than 15 years.
The regulator has worked together with the Office of Fair Trading, as well as the Competition and Markets Authority, to investigate the huge market share held by the 'Big Six' suppliers as well as vertical integration: the process where companies own both the power station and distribution system.
Defending the UK energy companies however, Cornwall Energy - a consultancy commissioned by Energy UK - said: "The household markets are seeing an erosion of major suppliers' shares.
"The five per cent-plus shares of the household electricity, gas and dual markets held by medium-sized and smaller suppliers at 31 January 2014 are the highest they have ever been since competition started in the late 1990s."
Similarly, British Gas parent company, Centrica, claimed the energy market was "intensely competitive" with prices.
Energy UK chief, Angela Knight, added: "We are more competitive than most of Europe: many countries don't have the plural market we have."
Not all energy supplier bosses agree with Energy UK however. Late last year, E.On chief executive Tony Cocker told MPs on the Energy and Climate Change Committee very directly: "We need to have a very thorough Competition Commission inquiry."
And with a 95% share of the energy market still held by the 'Big Six' energy suppliers, Ofgem is likely to push ahead with its recommendations - set to be made on Thursday (27 March).
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