Rail journeys will be disrupted during both May bank holiday weekends as more than 900 engineering projects are carried out.
Several sections of the West Coast Main Line will be closed from May 4-6, including at London Euston and near Crewe and Glasgow.
Network Rail, the government-owned company responsible for Britain’s rail infrastructure, warned that this will have a “major impact” on journeys, with Virgin Trains and London Northwestern Railway among the operators affected.
Alternative routes will be busier than normal and travel times will be extended.
The closure comes just two weeks after London Euston was shut over Easter.
There will be more changes to services on the West Coast Main Line as further work is carried out during the second bank holiday weekend next month, which runs from May 25-27.
During both May bank holiday weekends there will be disruption to Thameslink services to and from London St Pancras International, while buses will replace trains between Shenfield and Southend Victoria.
Engineering work will affect South Western Railway trains from London Waterloo to Clapham Junction and Barnes from May 4-6, and there will be no trains between Ipswich and Norwich from May 25-27.
Network Rail said it carries out major engineering projects over bank holidays to minimise the impact on passengers, as the railway is up to 50% quieter than usual over those periods.
The firm’s chief executive, Andrew Haines, said: “Passengers want and deserve a more reliable railway, and over the May bank holidays thousands of railway workers will be out on the track and working behind the scenes to deliver just that.
“While most of the railway network will be open as usual, some routes will be closed, so if you are thinking about travelling please plan ahead.”