https://www.leicester.gov.uk/media/180873/leicester-and-leicestershire-rail-strategy.pdfSection 9.2
Services to Swindon and Bristol (and possibly onwards to the West Country) would be routed via the Midland Main Line, East West Rail Western section and the Great Western Main Line, potentially serving:
• Bedford • Bletchley • Bicester • Oxford • Didcot • Swindon • Bath • Bristol
Clearly, completion of the East West Rail (EWR) “Western Section†throughout between Oxford and Bedford, currently planned for the end of CP6▸ in 2024, is a prerequisite for introduction of these services.
Capacity issues would also affect the Midland Main Line between Kettering and Bedford, where informed opinion states that only one additional main-line path is available (although accurately determining railway capacity, dependent as it is on a number of variable parameters including track layout, signalling design, line speeds, rolling stock performance, stopping patterns etc. is notoriously difficult). However many spare paths are actually available, there will, as discussed elsewhere, be competing views on the best use to which they can be put.
There are also separate issues regarding capacity at Oxford (which would, at east to some extent, be addressed in the large-scale redevelopment at Oxford station proposed in Control Period 6 and beyond, and on the Great Western Main Line both between Oxford and Didcot and west thereof towards Swindon. A stop at Didcot could be achieved with the current station layout at the expense of a time-consuming reversal, or new platforms would be required on the west curve connecting the Oxford route with the Main Line towards the west.