The Great Western Society (GWS) was offered the use of the former Didcot locomotive depot, taking it over in 1967. In the 1970s, the society negotiated a long-term lease with BR which was to expire in 2019. But this was subject to a six-month termination clause which could force the GWS to quit the site, and which could be operated at any point in time by lease-holder Network Rail (NR).

In an attempt to secure a long-term future for the society, in 2002 the GWS opened negotiations with NR to either purchase the site or extend the lease. In a letter dated May 2007, NR informed the GWS that they were prepared to sell the site subject to Office of Rail Regulation (ORR) approval.
It had been thought the site could be subject to need as a depot, either due to: the rebuilding of Reading station; a Crossrail project depot; or the Intercity Express Programme. After expressing some concern at the slow speed of negotiations at the GWS annual meeting in September 2008, NR wrote to the GWS to advise that the site was no longer available for sale, and although a lease extension was still on offer it was still subject to the previous six-month termination clause.

The GWS then wrote to their local MP Ed Vaizey, and placed any long-term development plans on hold. As of 6 October 2011 Richard Croucher (Chairman of the Great Western Society) signed a new 50-year lease with Network Rail, therefore preserving the site for at least another 50 years.