Train bosses are are urging Northampton passengers not to travel London over the August bank holiday.
No trains will run in or out of London Euston on 26 and 27 August while work is carried out on a major power supply.
The Euston shutdown will affect all services on the West Coast main line, which passes through Northampton, and is expected to make all train services extremely busy.
Passengers from Northampton are being urged not to travel to the capital by train over the bank holiday weekend unless essential.
Those planning to attend cultural or sporting events in the region are encouraged to plan ahead and allow extra time for their journeys.
Antonia Buckland, high speed rail sponsorship director for Network Rail, said: “The advice to passengers planning travel to or from Euston station this bank holiday is clear: plan your journeys on days other than Saturday and the Sunday and only travel by train on those days if absolutely essential. If you do travel, trains will be busier than usual, journeys will take longer and unless you have reserved one, you won’t be guaranteed a seat.
“Travel between Scotland, the north west, West Midlands and London on the Saturday and Sunday is discouraged and the whole rail industry - Network Rail, HS2 Ltd and train operators - is working together to give passengers plenty of warning and information about the planned disruption.”