On cold days this winter, that could require exceptionally high prices in Britain, adding to the pressure on households and businesses following more than a year of high gas prices. If supplies in Europe worsens, there is a risk some countries will curb exports.
Aurora Energy Research estimates that the UK will need to import at least 10pc of its gas from the EU this winter to meet demand.
However, S&P Global Commodity Insights forecasts that Britain will be a net exporter to the EU this winter, because LNG shipments will continue to arrive.
It is likely to still need some EU imports on individual cold days, however.
Ying Chin Chou, a senior analyst at S&P, said that every one degree decrease in temperature can increase demand for gas for heating by 10-15 million cubic metres (mcm).
She added: “Demand can escalate quite quickly.”
S&P believes gas demand in Britain will in any case be 40mcm per day lower than normal this winter, or about 15pc less, as soaring energy bills drive cuts in demand, among other factors.
Last week, Centrica won permission to reopen its Rough natural gas storage site in the North Sea, which closed in 2017.
However, it remains in talks with ministers about financial support for the site over the long term, and has not set a date for re-opening.
John Redwood, the Tory MP who is tipped to return to government if Liz Truss wins the Tory leadership contest on Monday, said it was a strategic “mistake” not to have more storage.
“Of course, I think we need more gas storage but my number one urging for many years has been getting more of our own gas out of the North Sea, and onshore where local communities go along with it.
“But the UK position is an awful lot stronger than the German or Italian position, which were much more dependent on Russian gas.”
A spokesman for the Business Department said: “When the market price is higher Europe, gas flows to the Continent. When the price is higher in the UK, gas flows back home. This is driven entirely by the market, not by Government.
“Britain is at a strategic advantage compared to other countries in Europe. The UK’s secure and diverse energy supplies will ensure households, businesses and industry can be confident they can get the electricity and gas they need.”