Between 2 December 2019 and 2 January 2020, the National Union of Rail, Maritime and Transport Workers (RMT) undertook 27 days of strikes.

[7] In February 2016, the DfT announced that two companies, FirstGroup and Stagecoach, had been shortlisted to bid for the next South Western franchise.

[15][16][17] The Competition & Markets Authority (CMA) held an inquiry into the awarding; during July 2017, it sought undertakings from First/MTR that it would not abuse its monopoly on services to the West of England, Dorset and Somerset, as FirstGroup also operated the Greater Western franchise in those regions.

[18][19] FirstGroup and MTR responded with an offer to implement a cap upon unregulated fares between London and Exeter as a mitigating measure; the CMA chose to accept this concession.

[21] By April 2018, concerns had reportedly grown over SWR's performance over previous months; there had been a noted rise in both the number of delayed services and outright cancellations.

[22] During July 2018, reports emerged that FirstGroup/MTR were in the process of renegotiating the SWR contract, allegedly due to the operator's inability to deliver on many of its promised improvements, as well as its declining performance and industrial action by its own staff.

[23] Between 2 December 2019 and 2 January 2020, the National Union of Rail, Maritime and Transport Workers (RMT) undertook 27 days of strikes.

These were in protest to the potential introduction of DOO (driver only operation) on SWR's new fleet of Bombardier-built Class 701 multiple units, which would thereby nullify the role of the guard.

[24] In January 2020, SWR announced that they were in discussions with the government regarding the future of the franchise following a £137 million loss, with termination of the contract being a possibility.

[25] By mid-2020, SWR had considerably curtailed its services in response to the significant decline of passenger travel amid the COVID-19 pandemic.

[34] The number of staff involved allowed SWR to remain capable of operating a minimal timetable on any of the planned dates for the strikes.

The majority of its passengers are on suburban commuter lines in inner and south-west London, Surrey, east Berkshire, and north-east Hampshire.

However, these restrictions apply only to cyclists boarding or alighting in the area bounded by Hook, Alton, Guildford, Reading and Dorking, in order to maximise available passenger space on the most crowded trains.

It operates as a fast service as far as Staines, with Reading trains only calling at Clapham Junction, Richmond, Twickenham and Feltham.

[52][53] On 24 June 2024 the first Class 458/4 entered public service, initially doing limited outer suburban routes such as London Waterloo to Weybridge via Addlestone.