The report concludes that Great Britain is expected to have sufficient gas supply capability to meet forecast demand this winter, maintaining positive supply margins under both normal and severe stress conditions. Forecast peak demand is expected to reach 493 million cubic metres per day (mcm/d), while total supply capability is assessed at 592 mcm/d.

The Winter Outlook follows the publication of a statutory consultation by Ofgem to enable National Gas to facilitate an agreement, at the request of the Government, to maintain Britain’s import capacity through continental interconnectors. The additional capacity has been made available for this Winter and has therefore had a positive impact on supply capability.

While this winter's outlook is positive, National Gas says continued progress on Government plans to reform security of supply arrangements will be vital to address enduring challenges in the years ahead.

As Britain’s Gas System Operator, National Gas’s role is to transport gas safely, securely and reliably across the country. However, in line with its licence obligations, it also plays an important role in publishing independent analysis and forecasts to support Government, regulators and industry make informed policy and commercial decisions.  

The Gas Winter Outlook 2026 also coincides with the publication of the National Energy System Operator’s Electricity Winter Outlook.

Key insights from the report include:

Demand

• Peak gas demand on a 1-in-20 winter day is forecast to increase by around 2% to 493 mcm/d, driven primarily by higher expected demand for gas-fired power generation.
• Peak gas demand for power generation is forecast to increase by 7%. On a day of peak gas demand, gas-fired power generation could reach around 27 GW at its highest point, reflecting the growing role gas plays in supporting electricity security when renewable output is low.
• Overall gas demand this winter is forecast to remain broadly in line with last year, with Great Britain's gas demand expected to decline by around 1%.

Supply

• Great Britain's gas supplies will continue to be underpinned by UK Continental Shelf production and Norwegian imports, supported by flexible sources including LNG, storage and continental interconnectors.
• Domestic gas production from the UK Continental Shelf is forecast to decline by around 5%, continuing its long-term downward trend.
• LNG imports are forecast to increase by around 6%, highlighting the growing importance of global imports within Britain's supply mix.
• The maintenance of interconnector import capacity has strengthened Great Britain's available supply capability ahead of winter and contributes to improved supply margins compared with last year's assessment. 

Glenn Bryn-Jacobsen, Director of Energy Systems and Resilience at National Gas, said:

"Our analysis shows that Great Britain is expected to have sufficient gas supply capability to meet demand throughout winter 2026/27, even under a range of very unlikely high-stress scenarios. This is a positive outcome, supported by the diversity of Britain's gas supply landscape, the resilience of our infrastructure and the coordinated actions taken across industry, Government and regulators over the past year.

"The analysis continues to demonstrate the critical role that gas, and the gas network, plays in safeguarding our country’s energy security. As Britain's electricity system becomes increasingly reliant on weather-dependent renewable generation, the flexibility and reliability provided by gas remains critical to maintaining energy security and keeping the lights on when renewable output is low.

"We will continue to monitor the market closely and work with Government, Ofgem, NESO and industry partners to ensure Britain remains well prepared for the winter ahead."

The Outlook further notes that while all key partners across government, regulators and industry recognise the challenges that evolving demand and supply patterns present for the ability of existing market arrangements to meet Britain’s security of supply requirements in future, and progress has been made, further action is required. This includes the timely publication of the full response to the Government’s Gas System in Transition: Security of Supply consultation.

Ian Radley, Chief Commercial Officer at National Gas, said:

“This year's Winter Outlook shows that while Britain's energy system continues to undergo significant change, gas remains essential to our everyday lives, heating 24 million homes, powering vital industries and keeping the lights on when the wind doesn’t blow and sun doesn’t shine.

“While overall gas demand is expected to fall over time, peak demand is expected to marginally increase this Winter and remain broadly unchanged for many years to come. At the same time, as domestic production continues to decline, Britain is becoming increasingly reliant on imported gas and other flexible sources of supply. Taken together, these factors underline the imperative of maintaining Britain's energy security in an increasingly evolving and uncertain landscape."

“The Government's Gas System in Transition programme is an important step forward, and recent action to strengthen resilience is welcome, however progress now needs to continue at pace. As Britain’s Gas System Operator, we’re committed to working together to support Government, regulators and industry to develop the longer-term measures required to maintain secure, reliable and diverse gas supplies in the years ahead.”

As with any outlook, the conclusions presented are based on information available at the time of publication. External events could still influence Great Britain’s gas market. As Great Britain is connected to European markets through interconnectors and to global markets through LNG, international disruptions, including geopolitical events, may affect market conditions.  

However, National Gas analysis indicates that only a rare and very unlikely combination of events, such as extreme weather coinciding with major supply disruption, would be expected to create material security of supply challenges. National Gas continues to maintain a range of operational, commercial and emergency tools to manage such circumstances should they occur.

National Gas will continue to work closely with Government, Ofgem, NESO and industry stakeholders, providing independent analysis and expertise to support Britain's energy security, ensuring that Great Britain is well-prepared for this year and beyond. 

You can read the Gas Winter Outlook 2026 report here. 

You can download the one page summary document here.