Spending on diesel by British train companies has hit a ten-year high, according to our new analysis.

Train operating companies are set to spend close to 40% more just to run the same level of service next year thanks to rising diesel costs and a long-term failure to electrify the network.

The analysis looked at official data from the government’s regulator, the Office of Road and Rail, and Network Rail, and found that British passenger railways’ diesel fuel bill this year will be £132 million higher than last year’s. 

Despite industrial electricity prices remaining high, electricity running costs for trains are projected to be two-thirds of the price of diesel per kilometre this year.

The difference in price is such that passenger train operators’ fuel bills will be £159.4million more in 2026-27 than they would be if the railway was fully electrified.

Whilst electricity costs have risen steadily over the past decade, volatile diesel prices mean that train operators have spent £1.35 billion more on fuel bills between 2015-16 and 2025-26 than it would have cost to run fully electric services.

With more services reliant on diesel compared to other European nations, Great Britain’s railway is “a glaring blind spot” in the government’s energy security strategy, campaigners warn. 

Official statistics show that progress on rail electrification has effectively ceased, with just 64km of route electrified in England in the last five years. 

The study singles out the Midland Mainline as a case in point. “Paused” indefinitely as part of the Labour Government’s comprehensive spending review in 2025, the project to put wires up between London and Sheffield has been started then stopped three times by successive governments first in 2012, then 2015 and again in 2021.

If this electrification work had been completed to Sheffield by late-2020 as planned, over £65.5 million would already have been saved on diesel costs by April 2026.The new diesel price highs will add an additional £18 million in running costs for the route in 2026-27 alone.

We are calling on the government to include a requirement for a long-term rolling-programme of electrification in the Railways Bill currently passing through Parliament.