Jason Mann, an energy expert at FTI Consulting who carried out a study for the Government on the electricity market last year, warned that balancing the South East would become increasingly difficult in the coming years as the grid grows more constrained.

He said: “As we go to a more intermittent renewables-based system, the challenges of balancing the grid are only going to become greater, particularly under the current national pricing regime.”

The issue has prompted the Government to weigh major changes to the electricity market, potentially by splitting it into regional zones that would each have their own electricity price.

This would encourage power companies to build plants closer to where electricity is needed.

FTI, in analysis for energy regulator Ofgem, found it would lower bills for consumers in every region due to the amount of money that would be saved across the system.

But the move is strongly opposed by wind farm developers, who have warned that making big regulatory changes now will deter investment and throw Labour’s 2030 power grid target into doubt.

The ESO is understood to have urged the Government to adopt zonal pricing.

On Tuesday, a spokesman said: “The ESO’s analysis in respect of zonal pricing supports the strategic build out and operation of Britain’s electricity system in a manner that is efficient and ensures that all networks and assets are utilised to their maximum.”

A Department for Energy Security and Net Zero spokesman said: “This Government is committed to boosting Britain’s energy security.

“Our mission is for clean power by 2030 because this is the best way to achieve energy independence and protect billpayers.

“We have a well-established system in place to secure our electricity capacity needs with reliable, affordable power for future years to come.”