Responsibility for running train services was handed to private companies during the 1990s, and since then there has been a boom in rail usage.

But a number have faced criticism over both fares and reliability, with critics saying privatisation has led to an inefficient and fragmented system.

During the coronavirus pandemic, the government in effect took control of much of the railways.

Several train companies in England moved onto contracts where they get a fixed fee to run services, and the taxpayer carries the financial risk.

Four major operators – East Coast Mainline, TransPennine, Northern and South Eastern (LNER) – have been taken under public control and are being run by the government’s operator of last resort.

Transport for Wales was brought under Welsh Government control in 2021, and Scotrail was taken over by the Scottish Government the following year.

South Western Railway has more than 1,500 services scheduled to run per weekday in south west London and the south of England.

It operates across southern England and is a key commuter service into London.

Train operator c2c runs services between Fenchurch Street and Shoeburyness, and serves 26 stations in east London and south Essex.

Greater Anglia runs services between London, Norfolk, Suffolk, Cambridgeshire Hertfordshire and Essex.

The rail system has also faced strain under two years of strike action across England, Scotland and Wales.

In September, train drivers accepted a pay deal that sought to bring an end to the row over remuneration and working conditions.

Ms Alexander also addressed the deal on BBC Breakfast and said it was “absolutely imperative that we found a way to break the deadlock” and felt it was important to “reset the relationships” with trade unions.