The Department for Energy Security and Net Zero (DESNZ) consultation on the gas system closed on 18 February 2026, according to the government's statutory security of supply report published on 17 December 20251. The report describes the consultation, published in November, as the first step in a programme of work to manage the challenges facing the gas sector and ensure security of supply in the long term1.
The report sets out the government's stated approach to gas security in three parts: accelerating efforts to decarbonise and electrify the economy, which it says will over time reduce gas demand and exposure to fossil fuels; working with the gas industry and market as supply and demand patterns change; and continued work by DESNZ and Ofgem with National Gas, the gas system operator, and with NESO, the National Energy System Operator1. The report says the consultation aims to ensure sufficient and resilient gas infrastructure and to understand how government can best provide insurance for low-probability, high-stress scenarios1.
"DESNZ is addressing this through the Gas System in Transition: Security of Supply consultation published in November, the aim of which is to ensure sufficient and resilient gas infrastructure and to understand how we can best provide insurance for low-probability, high-stress scenarios."
On gas import capacity, the report states that INT has held an open season on capacity sales and reduced capacity from 73mcm/d to 61mcm/d from 04 November 2025, and that it announced plans to reduce import capacity to 36mcm/d from 01 October 20261. National Gas decided in June 2025 that significant volume growth from last year's tender would be required1. The report says gas reserves from the UK Continental Shelf are continuing to deplete for geological reasons, and that over the next four years the changing supply mix is expected to coincide with a robust, oversupplied global LNG market1.
The report covers electricity as well as gas. It states that NESO forecasts sufficient electricity capacity to meet this winter's demand, with a derated margin of 6.1GW (10.0%) of the Average Cold Spell peak demand, an increase from 5.2GW (8.8%) last winter and the highest predicted margin since 20191. It gives a Loss of Load Expectation of below 0.1 hours per year against a standard of three hours per year1. On the Capacity Market, the report records that the T-1 auction for Delivery Year 2025/2026 concluded on 5 March 2025 and secured 7.9GW of de-rated capacity at a clearing price of £20/kW per year, and that the T-4 auction for delivery year 2028/2029 concluded on 11 March 2025 and secured 43.1GW of de-rated capacity1. It states that £1.25 billion was paid out to CM agreement holders for the 2024/25 Delivery Year, and that the next CM auctions will be held in March 20261.
| Item | Figure | Date |
|---|---|---|
| T-1 auction, Delivery Year 2025/2026 | 7.9GW de-rated capacity, £20/kW per year | Concluded 5 March 2025 |
| T-4 auction, delivery year 2028/2029 | 43.1GW de-rated capacity | Concluded 11 March 2025 |
| Winter 2025/26 derated margin | 6.1GW (10.0% of ACS peak demand) | This winter |
| INT import capacity reduction | 73mcm/d to 61mcm/d | From 04 November 2025 |
| Further INT import capacity reduction | To 36mcm/d | From 01 October 2026 |
Why it matters for households
Gas remains a vital component of Great Britain's energy mix, the report says, continuing to play a key role in heating, industry and power generation1. Most UK homes depend on gas for heat, so the shape of the gas system over the next four years bears directly on how secure that supply is. The report's conclusion is that GB is expected to have the ability to access and secure sufficient supplies of electricity and gas to meet consumers' demands over the short and long-term, an assessment covering the next four calendar years1. It also notes that the role of gas is expected to evolve in the longer term from providing base load supply to playing a key part in ensuring system flexibility1.
For a household, the practical questions are about the infrastructure behind the meter and the wider system it sits on. The energy security and household independence guide sets out what homes can control directly. On the electricity side, the Capacity Market is the mechanism that pays for firm capacity, and the report describes it as technology neutral and intended to ensure security of supply at least cost to consumers1. How that mechanism works is explained in the Capacity Market guide. The role of the system operator in planning and balancing supply is covered under NESO, and the department behind the consultation is described in the DESNZ guide. The consultation itself sits within the wider process described in energy consultations and how policy is made.
What happens next
The consultation closed on 18 February 20261. The report states that the next Capacity Market auctions will be held in March 20261. It also records that INT plans to reduce import capacity to 36mcm/d from 01 October 20261. No outcome of the consultation, and no government response to it, has been reported.