In just ten years energy bills have doubled to Â£1,250 - a factor that has left around 5.5 million households in the United Kingdom facing fuel poverty.
Ofgem have urged the 'big six' - which includes EDF Energy, npower, British Gas, E.On, SSE and Scottish Power - to implement changes to tariffs that are expensive or difficult to understand or suffer tougher punishment.
It is thought that Ofgem could implement price controls within the next ten years if the warning isn't successful.
A comment from Ofgem regarding the issue, read: "Parliament has given us the task of trying to create an effective market where competition is the downward pressure on prices.
"We think that's the way to go, although we haven't ruled out regulation, particularly for more vulnerable customers, if our reforms don't work."
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