Question to the HM Treasury:

To ask His Majesty's Government what is the tax cost of train operators using red diesel instead of paying full fuel tax.

Qualifying locomotives for passenger and freight trains, and rail maintenance vehicles can use red diesel for propulsion. The Treasury does not hold information on the cost of rebated fuel used specifically by train operators.

To assist the Noble Lord, I can point to the most relevant published statistics available. HMRC’s non-structural tax reliefs publication sets out the overall estimated Exchequer cost of the rebate for red diesel (and kerosene used as fuel in an engine), while DESNZ’s Digest of UK Energy Statistics provides data on petroleum products consumed by the rail sector.

Although these publications do not provide a separate official estimate for train operators, they provide the best available published information on the overall cost of the relief and the scale of rail-sector fuel use.