The process was very controversial at the time, and still is, and its success is hotly debated – with the claimed benefits including a reduced cost to the taxpayer, lower fares, improved customer service, and more investment. Despite opposition from the Labour Party, who gained power in 1997 under Tony Blair, the process has never been reversed wholesale by any later government, and the system remains largely unaltered. A significant change came in 2001 with the collapse of Railtrack, which saw its assets passed to the state-owned Network Rail (NR), with track maintenance also brought in-house under NR in 2004. The regulatory structures have also subsequently changed.
The Guardian
https://www.theguardian.com/uk-news/2018/jan/07/britains-rai...
Citylab
https://www.citylab.com/transportation/2012/09/why-britains-...
Science Direct
https://www.sciencedirect.com/science/article/pii/S015599821...