National Grid has told an emergency coal power station to start warming up as the country braces for a cold snap on Tuesday.
The West Burton A plant near Retford in Nottinghamshire will be placed on standby to meet demand if energy use surges as temperatures drop.
The plant is one of three that were due to close in September 2022 but have been kept online in case needed amid concern about energy security this winter. They have been warmed up several times so far this winter, but not yet used.
National Grid did not specify the trigger for the request. However, it comes as the Met Office is predicting a cold snap for up to a fortnight from Monday night, with temperatures set to drop below freezing in some parts of the UK.
Widespread strikes are also set to take place in France on Tuesday over pension reform, with an impact on nuclear power output. This has a knock-on effect in Britain as the markets are connected by power cables under the Channel.
A spokesman for the National Grid's electricity system operator (ESO) said: “This notification is not confirmation that the unit will be used on Tuesday, but that it will be available to the ESO, if required.
“The ESO as a prudent system operator has developed these tools for additional contingency to operate the network as normal. This does not mean electricity supplies are at risk.“
It comes as Europe is set to end the winter with record levels of gas reserves, according to new forecasts which raise hopes this winter’s energy crisis will not be repeated next winter.
Mild weather, high prices and efforts to save energy have helped cut demand for the fuel which is used to heat homes and generate electricity.
Cornwall Insight, an energy market analyst, estimates gas storage sites in Europe will still be 45-61pc full by the end of this winter.
That would make preparing for next winter less challenging, with Cornwall estimating stores could be 97pc full by the end of September.
The optimistic outlook raises hopes of avoiding another price crisis, and is a further sign that Russia’s ability to weaponise energy is weakening.
Cuts in Russian supplies of gas to Europe after its invasion of Ukraine in February 2022 worsened a surge in prices in Europe and Britain, feeding high inflation and a cost-of-living crisis.
Prices have cooled in recent weeks back to pre-war levels, although they are about double the long-term average.
Europe and Britain have been trying to diversify sources of gas supply, buying more from the US, as well as shift towards other sources of energy.
Britain has always been far less dependent on Russian gas than Europe, but the two markets are connected via pipelines and prices are similar.
In a report, Cornwall Insight said: “The immediate focus of governments, analysts, and market participants will be on whether Europe is past the worst of the crisis, or whether 2023 will see a repeat of the high prices and physical supply fears of 2022.
“One key factor that will determine this will be the level of European gas storage inventories as we exit this winter.”
The previous record for gas storage stocks at the end of winter was 54pc, in 2020.
The ease with which stores will be maintained is uncertain, however, with risks arising from factors such as Chinese demand and the weather.
Cornwall said: “There still remain meaningful and novel uncertainties and risks.
“Any single factor is capable of influencing the pace and pattern of storage refill, and perhaps more pertinently, changing the cost paid to achieve it.”
But it added some of the “panic” which drove markets last year had eased, helping to keep prices down.