Several units have been subleased to other operators, including Chiltern Railways, Abellio ScotRail, and TransPennine Express, for passenger services, hauling various rakes of carriages to do so, in some cases being outfitted with Association of American Railroads (AAR) push-pull apparatus.

[8] Accordingly, management examined several alternatives that could potentially be operated with greater profitability while also being practical for the company's core business of transporting nuclear materials by rail.

[8] It also incurs a higher operating cost than several contemporary locomotives, along with a relatively high rate of wheelset wear and a less than hospitable cab environment.

[8] In light of these factors, by 2009, DRS were convinced that a clean-sheet approach would be needed for its technical requirements, with management intended to not only support the business' core activities but without any subsidy but also increase its locomotive fleet.

Various manufacturers and their platforms were examined, including Brush Traction, General Electric, Bombardier, Siemens, with particular attention paid to the British Rail Class 70.

[8] Areas of modification extended beyond the physical bodyshell and the mechanical systems, as British railway regulations necessitated wiring changes and the fitted equipment.

[8] The development effort, which took roughly 18 months from start to finish, was greatly aided by the firm's experience from prior work undertaken in the manufacture of the British Rail Class 67 locomotive.

[8] On 5 January 2012, DRS announced it had placed an order with Vossloh for fifteen 100 mph (160 km/h) Eurolight locomotives for both intermodal and passenger work; these would be leased from Beacon Rail and the first example to be delivered during late 2013.

[8] The Class 68 incorporates an identical vehicle control unit and driver's advisory system to those fitted on the standard EUROLight platform.

[22][23] These locomotives have been painted in Chiltern's silver Mainline livery and are fitted with Association of American Railroads (AAR) push-pull equipment, which allows them to operate with Mark 3 coaching stock sets.

[24] Abellio ScotRail sub-leased two Class 68s, to haul sets of six Mark 2 coaches, for use on peak hour services on the Fife Circle Line.

[25] TransPennine Express (TPE) sub-leased fourteen Class 68 locomotives (68019 to 68032) from DRS, for initial use on the Liverpool Lime Street to Scarborough route.

[citation needed] In August 2023, TransPennine Express announced plans to withdraw its Class 68 fleet, as well as its Mark 5A coaches, from the December 2023 timetable revision;[29] however the sets were still leased by TPE until May 2024, and remain in storage.