Passengers from Norfolk and Suffolk will face longer journeys to London at weekends again for the first three months of 2018 as Network Rail engineers return to install new track and overhead lines on the route to Liverpool Street.

There will be no through weekend trains from the region to the capital in February and March – and no through Sunday services after January 14.

The disruption will continue until the long Easter weekend – March 30 to April 2 – after which no firm plans have been made by Network Rail.

However a spokeswoman for the infrastructure company said there was likely to be disruption during the two bank holiday weekends at the beginning and end of May as engineers worked to complete the line improvements before the start of Crossrail services on the new Elizabeth Line at the end of 2018.

When lines are closed, trains will finish at Ingatestone or Witham with a bus link to the Central Line tube station at Newbury Park – a move which adds at least 30 minutes to any journey to London.

Network Rail says it is now about to start the final year of work upgrading the track and overhead wires – many of which date from the 1950s.

It says the new equipment should be more reliable and will allow trains to continue whatever the weather conditions – at present trains have to slow down when it is very hot.

Meliha Duymaz, Network Rail's route managing director for Anglia, said: 'This work is crucial to improving rail travel in the East Anglia region, to provide more reliable services and improved connections across London.

'The number of people travelling by rail continues to grow and this investment programme forms a key part of our Railway Upgrade Plan to support this demand. I'd like to thank passengers for their patience while we carry out this work.'

Jamie Burles, Greater Anglia managing director, said: 'This work is vital for the modernisation of the railway in East Anglia, which both Network Rail and Greater Anglia, are committed to.

'We appreciate that engineering work is inconvenient to customers who would rather stay on the train for the whole of their journey. I would like to reassure people that we will make sure they can still complete their journeys, even if part of it is by bus.'