Major work at London King’s Cross station will lead to service changes at many stations later this week.

The work will mean that no trains will be running to or from London King’s Cross, Moorgate or St Pancras International via Finsbury Park between Friday and Sunday (February 26 to 28).

This is part of a £1.2billion upgrade of the East Coast Maine Line, Network Rail, Thameslink and Great Northern.

There will be temporary changes to the signalling at King’s Cross during the closure.

The following changes to services will be in place:

• Friday 26 February – Trains to and from Cambridge and Peterborough will start and end at Potters Bar, where passengers can use replacement buses to connect to alternative rail or London Underground services. Trains to and from Welwyn Garden City will start and end at New Barnet and services to and from Stevenage via Hertford North will start and end at Gordon Hill, with replacement buses running to Alexandra Palace.

• Saturday 27 February – Trains to and from Cambridge and Peterborough will start and end at Stevenage. Trains to and from Stevenage via Hertford North will start and end at Gordon Hill.

• Sunday 28 February – Trains to and from Cambridge and Peterborough will start and end at Hitchin. Services to and from Stevenage via Hertford North will be extended to Letchworth Garden City and will start and end at Gordon Hill.

Passengers who need to make essential journeys are strongly advised to check in advance via National Rail Enquiries, at EastCoastUpgrade.co.uk or on the Thameslink and Great Northern websites and allow plenty of time.

Jenny Saunders, Great Northern and Thameslink Customer Services Director, said: “This work at King’s Cross will improve reliability for everyone using the East Coast Main Line and enable improvements for long-distance services.

“However, with no trains running south of Potters Bar, New Barnet and Gordon Hill this Friday and other changes over the weekend, passengers making essential journeys will need to take buses to connect with services into London and this will take longer. Full details are available on our Great Northern and Thameslink websites.”

Between March 1 and early June, teams will carry out work to improve the track layout just outside King’s Cross station. The complex work will see the current layout, which was laid 40 years ago, lifted, replaced and realigned, creating smoother, more punctual and more reliable services for passengers.

Work will also take place to reopen a railway tunnel, which has been out of use since the 1970’s. This will provide two additional tracks, reducing congestion and making it easier for trains to enter and exit the historic transport hub.

The work taking place at King’s Cross over the next three months is the main stage of the East Coast Upgrade works at the station and follows months of activity. Once the work is completed in June, teams will have installed more than 6km of new track and 15km of overhead lines, which are used to power trains.