NEW light was shone on Britain’s privatised energy “shambles” yesterday after the National Grid revealed shortages could force factories to shut down this winter. 

Britain’s energy systems operator said that a recent spate of power plant closures had reduced electricity reserves to just 4.1 per cent — the slimmest margin in eight years. 

The National Grid’s new winter report raised the prospect of unprecedented emergency measures being taken in the event of freezing weather. 

Extraordinary steps that could be taken include industries being paid compensation to stop production in order to keep household lights on. 

GMB national energy secretary Gary Smith said the report revealed that the Con-Dems’ energy privatisation policy was in “disarray.”

“This isn’t a policy, it is a shambles,” he said. 

“There needs to be a radical look at the energy sector to take account of evidence that market-style solutions, that invariably involve massive subsidies, have failed.

“It is a natural monopoly, so market-style solutions will fail or deliver power that is too expensive.

“There has to be planning to bring on-stream enough capacity in the electricity sector.”

Firing up unused power plants and dimming the lights by reducing voltage are among other emergency plans.

Profiteers would pay for the contingencies by putting an extra £1 on household bills.

Watchdog Ofgem senior partner Rachel Fletcher claimed it was a “very small price to pay for ensuring the security of supply that we all expect from the British energy system.”

But technical union Prospect deputy general secretary Garry Graham said there is a “very real risk that the lights may go out.”