Railway services on the East Coast Main Line between Grantham and London will be disrupted by a three-day closure of Kings Cross Station as part of the £1.2 billion upgrade of the East Coast Main Line, starting from today.

Network Rail has advised people to "only travel if absolutely necessary" tomorrow and Sunday.

Network Rail is improving the track layout at King's Cross and reopening a disused tunnel in the main stage of a £1.2billion upgrade of the East Coast Main Line.

Work will allow more trains to enter and exit the station, reduce congestion and bring smoother, more reliable journeys for passengers.

Since the main stage of work on the £1.2billion East Coast Upgrade got underway at King's Cross in March, platform edges have been demolished, track has been lifted and overhead line equipment removed.

Hundreds of workers have been on site on site 24/7 to rebuild them and replace and realign the track.

Before platforms 0-6 at King's Cross can reopen for passengers and work can begin to lift the track at platforms 7-11, vital changes need to be made to the signalling, which is why the three days of work today, tomorrow and Sunday is required.

Friday 23 April

Great Northern and Thameslink services that usually run to/from London Kings Cross will start/end at Finsbury Park for connections with London Underground services to King's Cross.

Thameslink services to/from London St Pancras International and Great Northern services to/from Moorgate will continue to run. For the easiest journey, passengers travelling to or from central London are strongly encouraged to use these services instead to avoid the long walk between the National Rail and Underground platforms at Finsbury Park.

LNER trains to/from the North of England and Scotland will start/end at either Peterborough or Stevenage, where passengers can change onto Thameslink train services to/from St Pancras International.

Grand Central will run a reduced service between Sunderland/Bradford and Finsbury Park.

Hull Trains will not run.

Saturday 24 and Sunday 25 April

No trains will run to/from London King's Cross, Moorgate or to/from London St Pancras International via Finsbury Park.

Trains will run between Peterborough and St Neots, between King's Lynn, Cambridge and Letchworth Garden City, and between Welwyn Garden City and Potters Bar only. A number of rail replacement bus routes will connect with alternative rail services or London Underground lines for onward travel into London.

LNER trains to/from the North of England and Scotland will start/end at either Peterborough or St Neots. A replacement coach service will run between St Neots and Bedford, where passengers can change onto Thameslink train services to/from St Pancras International.

Grand Central and Hull Trains services will not run to or from London.

People should continue following the latest Government guidance and minimise travel where possible.

Passengers who have to travel are strongly advised to plan ahead, allow plenty of time for their journey and check before travelling via National Rail Enquiries, at EastCoastUpgrade.co.uk or with their train operator. The improvements to the track layout will continue until early June and train services will continue for the vast majority of this work. There will be no services to or from King's Cross on Friday 4, Saturday 5 and Sunday 6 June, and a full service will resume once again on Monday 7 June. Ed Akers, Principal Programme Sponsor for Network Rail's East Coast Upgrade, said: "It's strange seeing no trains, no track and no passengers across half of King's Cross as we make major progress to install the completely redesigned, simpler track layout. "Working with the wider rail industry, we've managed well with the complex track that was laid over 40 years ago, but this vital stage of the project will make it much more practical for trains coming in and out of the station – meaning more reliable journeys for passengers. "We've carefully planned this project to keep disruption to a minimum, and as we start work at platforms 7-11, trains will be able to use platforms 0-6. We want to thank passengers for their continued patience as we make essential changes to the signalling over the three-day closure." Jenny Saunders, Great Northern and Thameslink Customer Services Director, said: "On Friday 23 April, you'll still be able to travel with us, in accordance with the Government advice that applies at the time, but the trains which normally go to King's Cross will stop short at Finsbury Park so for journeys into Central London we recommend taking a train to St Pancras or Moorgate instead. "That weekend, 24 and 25 April, however, you shouldn't travel unless you absolutely have to. We'll have only a very limited train service and you're likely to have to change trains several times and maybe even queue to get on board." Further details can be found here.