Regulators have called for an investigation into the UK's Big Six energy suppliers amid soaring household bills and rocketing profits.
Ofgem's finding that aspects of energy firms' behaviour "would appear to be consistent with tacit coordination" has been denied by Centrica.
The inquiry into the 'Big Six' energy firms is a significant moment, but don't hold your breath, it will take the best part of two years.
An independent Scotland would be able to deliver a £70 cut in energy bills, and maintain the UK's energy supply.
Scottish Energy Minister Fergus Ewing explained:
– Fergus Ewing
Scotland's huge natural resources mean that we can supply electricity - reliably and affordably - and can help the UK keep the lights on and the bills down.
Scotland exports electricity to England and Wales every year - in 2012 a quarter of the electricity generated here helped keep lights on across the rest of the UK.
With the powers of independence we will deliver a permanent, ongoing annual cut in energy bills of £70 - by removing the Energy Company Obligation and the Warm Homes Discount from consumer bills.
The referendum on Scottish independence risks scaring away investors who will want to "hold on to their cash" until the UK is more settled, the Energy Secretary will warn.
– Energy Secretary Ed Davey
The energy sector in Scotland is booming and growing, with more and more jobs and attracting more investment.
I fear the economic and energy progress will be seriously affected by the uncertainty and disruption of independence, as investors will hold on to their cash rather than risk it.
The "uncertainty and disruption" caused by the looming referendum on Scottish independence will have a detrimental effect on progress in the economy and energy sector, a cabinet minister will warn.
Energy Secretary Ed Davey is expected to issue the warning later today as he launches the Government's latest Scotland Analysis paper in Edinburgh, focusing on gas and electricity.
The paper looks in detail at how the United Kingdom can maximise energy investment to support thousands of jobs and keep bills as low as possible.
The UK Government said its analysis shows that people in an independent Scotland would have to pay £3,800 per person to match the £20 billion the UK Government has committed towards decommissioning in the North Sea.
A spokeswoman for gas and electricity providers dismissed suggestions the sharp rise in complaints was a sign of a poor energy service.
Energy companies resolve most complaints "within a few working days", the spokeswoman for Energy UK said:
– Energy UK Spokeswoman
If a customer has any concerns relating to their bills, they should contact their provider as soon as they can, and if possible have an up-to-date meter reading to hand which will ensure their bill is as accurate as possible.
Energy companies work very hard to resolve problems and most complaints are fixed within a few working days with no more than a phone call.
The 224% rise in complaints is "worrying" and customers should shop around to find a better deal, the Government said.
A Department of Energy and Climate Change spokeswoman said:
– Department of Energy and Climate Change spokeswoman
The rise in the number of complaints is worrying.
We would advise consumers to shop around and switch to find a better deal, whether on cost or customer service.
Calls from fed-up energy customers have soared over the first three months of this year - a 224% rise compared to the same quarter last year, the energy sector's ombudsman said.
Between January and March 2014 complaints trebled to 10,638, compared with 3,277 received during the same period last year.
Over 2,000 customers complained they had not received bills, and a further 1,474 people were frustrated about billing charges.
Some 1,000 people complained about poor customer service.
Chief Energy Ombudsman Lewis Shand Smith said: "With energy complaints trebling in the first quarter of this year and problems relating to billing the greatest concern, increased transparency is something that should be addressed."
Ofgem has highlighted several key areas the Competition and Markets Authority should look at in its inquiry of the energy market, including possible tacit co-ordination and profits made by the 'Big Six'.
The energy watchdog has outlined the following areas:
- Customer trust: The review found that consumer trust had fallen with 43% of customers not trusting energy suppliers to be transparent with them.
- Entry barriers: The large suppliers own infrastructures such as power stations and supply businesses meaning it is difficult for new entrants to the market.
- Possible tacit co-ordination: Ofgem did not find evidence of explicit collusion between suppliers. However, the watchdog found evidence of possible tacit co-ordination in the timing and size of price announcements.
- Profits: The average profits for the 'Big Six' have increased from £3bn to £3.7bn in three years. Ofgem said it noted the increase and questioned suppliers saying that 5% is a fair margin.
The 'Big Six' energy firms "behave similarly" and "anticipate each other particularly on price rises" which leaves a market that is not competitive, Ofgem's Rachel Fletcher told ITV News.
The boss of Centrica, which owns British Gas, told ITV News the 'Big Six' energy firms are "absolutely not a cartel" after Ofgem's review found evidence of possible tacit co-ordination.
The energy watchdog said it did not find evidence of explicit collusion between the firms but said the timing and size of price announcements were part of the evidence that showed possible tacit co-ordination.
Sam Laidlaw told ITV News he "refutes totally" the idea that the 'Big Six' are a cartel and claimed that the energy market is "vibrant" and "very competitive."