The U.K. Department for Transport has indicated it may be reconsidering its position on the use of crop-based sustainable aviation fuel (SAF), opening the door for possible changes to the country’s SAF Mandate in the future. In late 2025, the department launched a public consultation process to gather evidence on whether fuels made from crops should be allowed under the mandate, reports Biodiesel Magazine.
On December 22, the department invited comments on SAF produced from crops, including energy crops, cover crops, and food and feed crops. The call for evidence is linked to the U.K.’s main SAF policy measures, which include the SAF Mandate that came into force in 2025, the Advanced Fuels Fund that supports early-stage SAF projects, and a revenue certainty scheme aimed at reducing financial risk for developers.
In announcing the consultation, the Department for Transport said the SAF Mandate provides long-term certainty by creating a legal framework that guarantees demand for SAF in the U.K. This, it said, helps businesses plan investments, build supply chains and make confident commercial decisions. The government added that any future changes to the mandate would only be considered if there is a strong justification and if such changes do not undermine policy stability or investor confidence.
The government said the SAF sector is expanding rapidly, and policy will need to ensure that the mandate delivers real reductions in greenhouse gas emissions while keeping costs manageable for consumers. It also said the mandate must align with the U.K.’s wider climate targets, work effectively with other low-carbon fuel schemes, support domestic production and adapt to technological progress.
As part of this process, the government is seeking evidence on the availability and cost of crop-based SAF feedstocks, the impact of such fuels on U.K. industries, and potential sustainability risks. It is also asking how regulation could address or reduce those risks.
Under the current SAF Mandate, fuel suppliers must meet two obligations: a main SAF requirement and a separate requirement for power-to-liquid fuels. The main obligation started at 2% of total fossil jet fuel supplied in 2025 and is set to rise to 9.5% by 2030 and 18.5% by 2040. The power-to-liquid requirement begins at 0.2% in 2028 and increases to 3.5% by 2040.
The mandate also places limits on the use of hydroprocessed esters and fatty acids (HEFA). HEFA fuels can meet the full obligation in 2025 and 2026, but their share will be capped at 71% in 2030 and reduced further to 35% by 2040.
At present, the SAF Mandate only allows fuels made from sustainable wastes and residues, recycled carbon sources such as non-recyclable plastics, or power-to-liquid fuels produced using low-carbon energy. SAF made from crops, including food, feed, energy and cover crops, is currently excluded.
All SAF used under the mandate must deliver at least a 40% reduction in greenhouse gas emissions. Additional sustainability rules apply to certain feedstocks, covering issues such as biodiversity protection, land use, soil carbon and waste management.
While the exclusion of crop-based SAF remains in place, the government said it is open to reviewing new or updated evidence. The current call for evidence is intended to assess the possible benefits, risks and trade-offs of using crops for SAF production.
The Department for Transport stressed that the consultation does not propose any immediate changes to the SAF Mandate. It said that if the evidence supports a review of feedstock rules, any changes would be subject to a formal consultation and would require amendments to existing legislation.
The consultation mainly focuses on energy crops, cover crops and food and feed crops, but the government has also invited comments on other types of crops not clearly covered by these categories.
The call for evidence opened on December 22, 2025, and will remain open until March 16, 2026. Further details are available on the Department for Transport’s website.
